You can still use the infotainment without signing into a Google Account. The only thing that's locked out is the Play Store and 3rd party apps (which you need the play store to download).
Can you use android auto? For the normal person your phone is a better place to get all that anyway. The few people driving as a full time job will find the cars built in stuff better but for most your phone had everything the rest of the time so you want to use that.
Can you use android auto? For the normal person your phone is a better place to get all that anyway. The few people driving as a full time job will find the cars built in stuff better but for most your phone had everything the rest of the time so you want to use that.