Android Auto hasn't been playing nice with Android 9 Pie. There have been reports left and right of numerous bugs: missing text notifications, a disruptive buzzing sound in calls, and frequent crashes. Fortunately, the Android Auto team is aware of these issues, and reports that it's fixed at least one — Android Auto version 3.5 should solve the crashing problem.
Previously, running Google Maps or Waze on a phone updated to Android 9 Pie with an Android Auto head unit resulted in the in-car display going black or Android Auto crashing and restarting entirely.Read More
Android Auto v3.5 fixes crashing on phones with Android 9 Pie [APK Download] was written by the awesome team at Android Police.