Android Auto on Raspberry Pi 3

Update: Finally someone built a headunit emulator for the Raspberry Pi which is working pretty good so far. Have a look at https://github.com/f1xpl/openauto.

Spoiler alert: It works (including touchscreen!!!), but it is extremely buggy and slow. I can not suggest it for daily use.

Install Android
Download and install the official developer preview of Android Things. Flash and boot the .img, just like you would do with Raspbian. Connect Ethernet and wait for Android to obtain an IP. Now connect to your Pi via ‘adb connect *IP*’.

Update Google Play Services
First you need to uninstall the shipped version of Google Play Services. Run ‘adb root’, reconnect adb and run ‘adb remount’ to make Android’s system partitions writable. Next remove Google Play Services by running ‘rm -r -f /gapps’. Now install the latest Google Play Services with ‘adb install’. Google Play Services require special permissions, so we need to install it as system app. Rename the Play Services folder in ‘/data/app’ and the ‘base.apk’ file in it to something like ‘GMS’ and ‘GMS.apk’. Copy the folder from ‘/data/app’ to ‘/system/priv-app’. Change file and folder permissions to match the other files and folders in ‘/system/priv-app’. Run ‘chcon -R u:object_r:system_file:s0 /system/priv-app/GMS’ to change SELinux context. After rebooting ‘pm list packages’ should now show ‘com.google.android.gms’.

Install Android Auto and required apps
Android Auto requires Google Search, Google Play Store, Google Maps and Google Play Music. Download the apk files and install them with adb.

Run Android Auto
‘adb shell am start -n com.google.android.projection.gearhead/com.google.android.gearhead.vanagon.VnLaunchPadActivity’. Do not sign in with Google, it will not work (like many other things).