Google maps not showing on carplay ios12

DaveRobbo wrote:

After installing ios12 I cannot add google maps or waze to the carplay home screen

Keep in mind that the 3rd party app (Google Maps, Waze) needs to be updated to support CarPlay.

With that said, yesterday Google released an updated version of the Google Maps app that supports CarPlay. Waze has not released their updated version yet

Just delete Google Maps and reinstall it. You may have to shut down and open system settings as well.