Music randomly stops in Android Auto

[stlhophead]

I have been using Android Auto for about three weeks now, the last couple days whenever I am listening to music it will randomly stop playing.  I have to navigate back to Spotify in AA and hit play to start playing music again.  This happens both for music downloaded to the device and playlists/songs that are streaming.

Restarting AA doesn't make a difference.  I thought it might have been some nanny feature (much like the hugely inconvenient "no browsing while moving" feature) but I am not convinced.

Any way to troubleshoot this?