Alright, to answer my own question now that I have had it longer than a week.
There is some weirdness, but not necessarily with Andoid Auto, but with how Spotify works through Android Auto. I might as well put it here, just in case someone else is having problems. I already posted it in the forums (where others are having this problem) and Spotify is going to pass it on to their developers.
Sometimes, when using Spotify in the car through Android Auto, and you disconnect the phone, it may or may not play when you reconnect it (after an indeterminate amount of time) . If you look at the screen, the song will appear to be playing, but nothing is playing through the speakers. You can get it working temporarily by switching to Google Music, playing a song, stopping song, switching back to Spotify. It will play again, but usually dies after 8-10 minutes again. Almost like it there are issues with Spotify talking to the bluetooth driver.
The solution I have found is going to the Spotify App from settings -> apps and doing a "Force Stop" on Spotify. Right swiping it from the task list or doing a "clear all" does not completely kill the task and you will have the same problem. If you kill the process each time you get out of your car, or before you reconnect it, it works fine. You can always reboot your phone if you like, but I found this quicker.
Again, I have had no other problems with the 2 Notes I had before (or with my kids Galaxy phones), but my V20 had this issue. I am only taking the time to post it here just in case someone else has this strange issue. It is more likely Spotify than Android Auto or the phone.
Facebook
Twitter
Instagram