okay so it was a bit different than the post but i did this:
settings ➔ apps ➔ sandboxed google play ➔ Android auto settings ➔ On the android auto screen just scroll down to the bottom where the about section is shown. ➔ Click on "version" 10 times to enable android auto developer settings.
➔ Once enabled go to the top right and click on 3 dots. Click on "Developer settings" ➔ Scroll down to " Unknown sources" ➔ Put a check mark on the setting and restart the phone.
Connect your phone normally to AA on your car and it should give you these missing apps!
i haven't tested yet but i will after work!