diff --git a/gearslip/src/main/AndroidManifest.xml b/gearslip/src/main/AndroidManifest.xml
index df6e0e7..b0cb40d 100644
--- a/gearslip/src/main/AndroidManifest.xml
+++ b/gearslip/src/main/AndroidManifest.xml
@@ -5,6 +5,8 @@
     <!-- The projected WebView loads real pages; without this every load fails silently. -->
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+    <!-- Lets an update Gearslip installed itself skip Android's prompt. -->
+    <uses-permission android:name="android.permission.UPDATE_PACKAGES_WITHOUT_USER_ACTION" />
 
     <!--
       Phone mirroring. Android refuses to hand over a MediaProjection unless a foreground
@@ -216,6 +218,14 @@
             android:name=".notify.TestMessageReceiver"
             android:exported="false" />
 
+        <receiver
+            android:name=".update.UpdateReceiver"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
+            </intent-filter>
+        </receiver>
+
         <service
             android:name=".mirror.MirrorService"
             android:exported="false"
diff --git a/gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UpdateViews.kt b/gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UpdateViews.kt
index 2a91c8d..6bbd816 100644
--- a/gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UpdateViews.kt
+++ b/gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UpdateViews.kt
@@ -171,6 +171,7 @@ private fun UpdateDialog(
 ) {
     val context = LocalContext.current
     var auto by remember { mutableStateOf(UpdateChecker.autoCheckEnabled(context)) }
+    var silent by remember { mutableStateOf(UpdateChecker.silentEnabled(context)) }
     val actionLabels = listOf(R.string.update_download, R.string.update_install, R.string.update_try_again, R.string.update_check_now).map { stringResource(it) }
     val action: Pair<String, () -> Unit>? = when (state) {
         State.Checking, is State.Downloading -> null
@@ -230,6 +231,29 @@ private fun UpdateDialog(
                     }
                     Switch(checked = auto, onCheckedChange = null)
                 }
+                // Silent installs ride on the automatic check, so the switch only shows with it on.
+                if (auto && !BuildConfig.DEBUG) {
+                    Row(
+                        Modifier
+                            .fillMaxWidth()
+                            .toggleable(silent, role = Role.Switch) {
+                                silent = it
+                                UpdateChecker.setSilentEnabled(context, it)
+                            }
+                            .padding(vertical = 4.dp),
+                        verticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        Column(Modifier.weight(1f)) {
+                            Text(stringResource(R.string.update_silent), style = MaterialTheme.typography.bodyLarge)
+                            Text(
+                                stringResource(R.string.update_silent_sub),
+                                style = MaterialTheme.typography.bodyMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                        Switch(checked = silent, onCheckedChange = null)
+                    }
+                }
             }
         },
         confirmButton = {
diff --git a/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateChecker.kt b/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateChecker.kt
index f8e7bfe..cc2a1fa 100644
--- a/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateChecker.kt
+++ b/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateChecker.kt
@@ -1,25 +1,31 @@
 package app.seb3thehacker.gearslip.update
 
 import android.Manifest
+import android.app.Activity
 import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
 import android.content.Context
 import android.content.Intent
+import android.content.pm.PackageInstaller
 import android.content.pm.PackageManager
+import android.hardware.usb.UsbManager
+import android.net.ConnectivityManager
+import android.net.NetworkCapabilities
 import android.net.Uri
 import android.provider.Settings
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
-import androidx.core.content.FileProvider
 import androidx.core.graphics.drawable.toBitmap
 import app.seb3thehacker.gearslip.BuildConfig
 import app.seb3thehacker.gearslip.GearslipActivity
 import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.SessionStatus
 import app.seb3thehacker.gearslip.notify.CarMotion
 import app.seb3thehacker.gearslip.notify.CarNotification
 import app.seb3thehacker.gearslip.notify.CarNotifications
+import app.seb3thehacker.gearslip.wireless.WirelessAuto
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -42,6 +48,10 @@ import java.security.MessageDigest
  * Nothing runs in the background otherwise, and nothing else is sent: the request is the same one
  * a browser makes for the release page. Debug builds never check on their own.
  *
+ * On Stable, a new version also installs by itself on Wi-Fi while no car is connected, without
+ * Android asking, once Gearslip has installed itself before. Android allows that only to the app
+ * that installed the current version, so the first update from a browser download still asks.
+ *
  * The APK is checked against the size and SHA-256 GitHub lists for it, and Android refuses an
  * update signed with a different key, so a bad download can't replace the app.
  */
@@ -72,6 +82,12 @@ object UpdateChecker {
     private const val KEY_CHANNEL = "channel"
     private const val KEY_NOTIFIED = "notified_version"
     private const val KEY_CAR_NOTIFIED = "car_notified_version"
+    private const val KEY_SILENT = "silent"
+    /** The version installing without a prompt, so the new one can say it updated. */
+    private const val KEY_SILENT_VERSION = "silent_version"
+    /** A version Android wanted confirmed: it isn't tried quietly again, the card and notification take over. */
+    private const val KEY_SILENT_REFUSED = "silent_refused"
+    private const val UPDATED_NOTIFICATION_ID = 4101
     /** Lets the car screen settle after plug-in, so the card isn't lost behind the first frames. */
     private const val CAR_DELAY_MS = 8_000L
     private const val CHANNEL = "updates"
@@ -97,6 +113,13 @@ object UpdateChecker {
         if (!on) NotificationManagerCompat.from(context).cancel(NOTIFICATION_ID)
     }
 
+    /** Whether a Stable update installs by itself on Wi-Fi with no car connected. On by default. */
+    fun silentEnabled(context: Context): Boolean = prefs(context).getBoolean(KEY_SILENT, true)
+
+    fun setSilentEnabled(context: Context, on: Boolean) {
+        prefs(context).edit().putBoolean(KEY_SILENT, on).apply()
+    }
+
     /** Which releases count as updates. Each channel also takes everything the one before it does. */
     enum class Channel { STABLE, BETA, ALPHA }
 
@@ -130,10 +153,27 @@ object UpdateChecker {
             install(context)
             return
         }
+        // Opened for a car (plugged in, or wireless found it): installing now would close Gearslip
+        // just as it connects.
+        val forCar = (context as? Activity)?.intent?.action in
+            setOf(UsbManager.ACTION_USB_ACCESSORY_ATTACHED, WirelessAuto.ACTION_CAR_NEARBY)
+        if (current is State.Ready) {
+            if (!forCar) installQuietly(context.applicationContext, current.release)
+            return
+        }
         if (current != State.Idle) return
         // A release found earlier still shows after Android closed the app.
         savedRelease(context)?.let { flow.value = State.Available(it) }
-        if (dueForCheck(context)) check(context)
+        val app = context.applicationContext
+        if (dueForCheck(context)) {
+            flow.value = State.Checking
+            Thread({
+                flow.value = checkNow(app)
+                (flow.value as? State.Available)?.let { if (!forCar) installQuietly(app, it.release) }
+            }, "gearslip-update").start()
+        } else if (!forCar) {
+            savedRelease(app)?.let { installQuietly(app, it) }
+        }
     }
 
     /**
@@ -150,6 +190,7 @@ object UpdateChecker {
                 flow.value = checkNow(app)
             }
             val release = foundRelease(app) ?: return@Thread
+            if (installQuietly(app, release)) return@Thread
             if (prefs(app).getString(KEY_NOTIFIED, null) == release.version) return@Thread
             if (notify(app, release)) prefs(app).edit().putString(KEY_NOTIFIED, release.version).apply()
         }, "gearslip-update").start()
@@ -250,8 +291,34 @@ object UpdateChecker {
         },
     )
 
-    /** Downloads [release], then opens the installer once the file checks out. */
-    fun download(context: Context, release: Release) {
+    /**
+     * Downloads and installs [release] without asking, when everything allows it: Stable, the
+     * switch on, Wi-Fi, no car, and Android already letting Gearslip install. Returns false when it
+     * didn't start, so the caller tells the driver the usual way.
+     */
+    private fun installQuietly(app: Context, release: Release): Boolean {
+        val ok = !BuildConfig.DEBUG && autoCheckEnabled(app) && silentEnabled(app) &&
+            channel(app) == Channel.STABLE && !carConnected && onWifi(app) &&
+            app.packageManager.canRequestPackageInstalls() &&
+            prefs(app).getString(KEY_SILENT_REFUSED, null) != release.version
+        if (!ok) return false
+        GearslipLog.i("update: installing ${release.version} without asking")
+        val current = flow.value
+        if (current is State.Ready && current.release == release) install(app, quiet = true)
+        else download(app, release, quiet = true)
+        return true
+    }
+
+    /** Not metered: Wi-Fi or ethernet, where 34 MB doesn't cost anyone. */
+    private fun onWifi(context: Context): Boolean {
+        val cm = context.getSystemService(ConnectivityManager::class.java) ?: return false
+        val caps = cm.getNetworkCapabilities(cm.activeNetwork) ?: return false
+        return caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
+            caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
+    }
+
+    /** Downloads [release], then installs it once the file checks out. */
+    fun download(context: Context, release: Release, quiet: Boolean = false) {
         if (flow.value is State.Downloading) return
         val app = context.applicationContext
         flow.value = State.Downloading(release, 0f)
@@ -267,21 +334,23 @@ object UpdateChecker {
                 GearslipLog.w("update: download failed: ${it.message}")
                 State.Failed(it.message ?: "The download failed. Try again.", release)
             }
-            if (flow.value is State.Ready) install(app)
+            if (flow.value is State.Ready) install(app, quiet)
         }, "gearslip-update").start()
     }
 
     /**
      * Hands the downloaded APK to Android's installer. The first time, Android wants the driver to
      * allow installs from Gearslip; that opens its settings page, and the install carries on when
-     * they come back.
+     * they come back. A [quiet] install never opens anything: if Android wants a confirmation, it
+     * falls back to the card and the notification.
      */
-    fun install(context: Context) {
+    fun install(context: Context, quiet: Boolean = false) {
         val ready = flow.value as? State.Ready ?: return
         // Installing closes Gearslip, which would drop the car screen mid-drive.
         if (carConnected) return
         val pm = context.packageManager
         if (!pm.canRequestPackageInstalls()) {
+            if (quiet) return
             installWhenAllowed = true
             context.startActivity(
                 Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES, Uri.parse("package:${context.packageName}"))
@@ -289,14 +358,111 @@ object UpdateChecker {
             )
             return
         }
-        val uri = FileProvider.getUriForFile(context, "${context.packageName}.logshare", ready.apk)
-        context.startActivity(
-            Intent(Intent.ACTION_VIEW)
-                .setDataAndType(uri, "application/vnd.android.package-archive")
-                .addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_ACTIVITY_NEW_TASK),
-        )
+        val app = context.applicationContext
+        Thread({
+            runCatching { commit(app, ready, quiet) }.onFailure {
+                GearslipLog.w("update: install failed to start: ${it.message}")
+                if (!quiet) flow.value = State.Failed("Android couldn't start the install. Try again.", ready.release)
+            }
+        }, "gearslip-update").start()
     }
 
+    /**
+     * Writes the APK into an install session. Android skips its prompt when Gearslip installed the
+     * version being replaced; otherwise [onInstallStatus] gets a screen to show for the driver.
+     */
+    private fun commit(app: Context, ready: State.Ready, quiet: Boolean) {
+        val installer = app.packageManager.packageInstaller
+        val params = PackageInstaller.SessionParams(PackageInstaller.SessionParams.MODE_FULL_INSTALL).apply {
+            setAppPackageName(app.packageName)
+            setSize(ready.apk.length())
+            setRequireUserAction(PackageInstaller.SessionParams.USER_ACTION_NOT_REQUIRED)
+        }
+        val id = installer.createSession(params)
+        installer.openSession(id).use { session ->
+            session.openWrite("gearslip.apk", 0, ready.apk.length()).use { out ->
+                ready.apk.inputStream().use { it.copyTo(out) }
+                session.fsync(out)
+            }
+            if (quiet) prefs(app).edit().putString(KEY_SILENT_VERSION, ready.release.version).commit()
+            val status = Intent(app, UpdateReceiver::class.java)
+                .setAction(UpdateReceiver.ACTION_STATUS)
+                .putExtra(EXTRA_QUIET, quiet)
+                .putExtra(EXTRA_VERSION, ready.release.version)
+            // Mutable: the installer adds the outcome to it.
+            val pending = PendingIntent.getBroadcast(app, id, status, PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_MUTABLE)
+            session.commit(pending.intentSender)
+        }
+        GearslipLog.i("update: handed ${ready.release.version} to Android's installer")
+    }
+
+    /** What the installer said about a session; on success Gearslip is replaced and this never runs. */
+    internal fun onInstallStatus(context: Context, intent: Intent) {
+        val app = context.applicationContext
+        val quiet = intent.getBooleanExtra(EXTRA_QUIET, false)
+        val version = intent.getStringExtra(EXTRA_VERSION)
+        val status = intent.getIntExtra(PackageInstaller.EXTRA_STATUS, PackageInstaller.STATUS_FAILURE)
+        when (status) {
+            PackageInstaller.STATUS_PENDING_USER_ACTION -> {
+                if (quiet) {
+                    // Android wants a tap, maybe because a browser installed this version. Don't
+                    // pop a screen up unasked: drop it, and the card and notification take over.
+                    GearslipLog.i("update: Android wants $version confirmed; leaving it to the driver")
+                    val session = intent.getIntExtra(PackageInstaller.EXTRA_SESSION_ID, -1)
+                    if (session >= 0) runCatching { app.packageManager.packageInstaller.abandonSession(session) }
+                    prefs(app).edit().putString(KEY_SILENT_REFUSED, version).remove(KEY_SILENT_VERSION).apply()
+                    val release = foundRelease(app) ?: return
+                    if (prefs(app).getString(KEY_NOTIFIED, null) != release.version && notify(app, release)) {
+                        prefs(app).edit().putString(KEY_NOTIFIED, release.version).apply()
+                    }
+                } else {
+                    @Suppress("DEPRECATION")
+                    val confirm = intent.getParcelableExtra<Intent>(Intent.EXTRA_INTENT) ?: return
+                    runCatching { app.startActivity(confirm.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)) }
+                }
+            }
+            PackageInstaller.STATUS_SUCCESS -> GearslipLog.i("update: $version installed")
+            else -> {
+                val message = intent.getStringExtra(PackageInstaller.EXTRA_STATUS_MESSAGE)
+                GearslipLog.w("update: install of $version failed ($status, $message)")
+                prefs(app).edit().remove(KEY_SILENT_VERSION).apply()
+                if (quiet) prefs(app).edit().putString(KEY_SILENT_REFUSED, version).apply()
+                else if (status != PackageInstaller.STATUS_FAILURE_ABORTED) {
+                    flow.value = State.Failed("Android didn't install it. Try again.", foundRelease(app))
+                }
+            }
+        }
+    }
+
+    /** The new version's first breath after updating itself: say so, since nobody was asked. */
+    internal fun onReplaced(context: Context) {
+        val app = context.applicationContext
+        val version = prefs(app).getString(KEY_SILENT_VERSION, null) ?: return
+        prefs(app).edit().remove(KEY_SILENT_VERSION).apply()
+        if (version != BuildConfig.VERSION_NAME) return
+        GearslipLog.i("update: now on $version, installed without asking")
+        if (app.checkSelfPermission(Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) return
+        app.getSystemService(NotificationManager::class.java).createNotificationChannel(
+            NotificationChannel(CHANNEL, "Updates", NotificationManager.IMPORTANCE_DEFAULT),
+        )
+        val open = PendingIntent.getActivity(
+            app, UPDATED_NOTIFICATION_ID,
+            Intent(app, GearslipActivity::class.java).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP),
+            PendingIntent.FLAG_IMMUTABLE,
+        )
+        val notification = NotificationCompat.Builder(app, CHANNEL)
+            .setSmallIcon(android.R.drawable.stat_sys_download_done)
+            .setContentTitle(app.getString(R.string.update_installed_title, version))
+            .setContentText(app.getString(R.string.update_installed_text))
+            .setContentIntent(open)
+            .setAutoCancel(true)
+            .build()
+        runCatching { NotificationManagerCompat.from(app).notify(UPDATED_NOTIFICATION_ID, notification) }
+    }
+
+    private const val EXTRA_QUIET = "quiet"
+    private const val EXTRA_VERSION = "version"
+
     /** The newest release with an APK that [channel] takes. Drafts never count. */
     private fun fetchNewest(channel: Channel): Release? {
         val stable = channel == Channel.STABLE
diff --git a/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateReceiver.kt b/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateReceiver.kt
new file mode 100644
index 0000000..7476510
--- /dev/null
+++ b/gearslip/src/main/java/app/seb3thehacker/gearslip/update/UpdateReceiver.kt
@@ -0,0 +1,19 @@
+package app.seb3thehacker.gearslip.update
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+
+/** The installer's answer about an update, and the new version's first start after one. */
+class UpdateReceiver : BroadcastReceiver() {
+    override fun onReceive(context: Context, intent: Intent) {
+        when (intent.action) {
+            ACTION_STATUS -> UpdateChecker.onInstallStatus(context, intent)
+            Intent.ACTION_MY_PACKAGE_REPLACED -> UpdateChecker.onReplaced(context)
+        }
+    }
+
+    companion object {
+        const val ACTION_STATUS = "app.seb3thehacker.gearslip.update.STATUS"
+    }
+}
diff --git a/gearslip/src/main/res/values/strings.xml b/gearslip/src/main/res/values/strings.xml
index 692183d..5b03bdf 100644
--- a/gearslip/src/main/res/values/strings.xml
+++ b/gearslip/src/main/res/values/strings.xml
@@ -302,6 +302,10 @@
     <string name="update_check_now">Check now</string>
     <string name="update_check_auto">Check automatically</string>
     <string name="update_once_a_day">Once a day</string>
+    <string name="update_silent">Install updates by itself</string>
+    <string name="update_silent_sub">Finished releases only, on Wi-Fi, when no car is connected</string>
+    <string name="update_installed_title">Gearslip updated to %1$s</string>
+    <string name="update_installed_text">Installed on Wi-Fi while no car was connected.</string>
 
     <!--  -->
     <string name="update_unplug_first">Unplug from the car to install. Installing closes Gearslip.</string>