Just rented a car with wireless Android Auto, and while it was convenient when it worked, it occasionally dropped the connection and I had to manually restart it (and sometimes it would refuse to connect). On one day where I was on a road trip, this happened several times.
Also, when I wanted to turn it off temporarily, there's no easy way to do so on either the phone or car. Gotta turn the car off or dive deep into infotainment settings. It looks like neither the auto manufacturers nor Google have thought this through.