I primarily use Spotify Premium on my Lumia 920 connect via bluetooth to by car (Mazda 3). Issues I have seen are:
1. Spotify is not able to play songs when connected to my car especially if I had previously used it to play in the car and I had turned off the car and turned it back on. The app comes up fine but when I select a song from a playlist - it just hangs. After a while it times out and returns to the playlist. Usually I have to ensure the app is completely turned off and restarted before it starts playing again.
2. Spotify looses association as a music player when it looses the bluetooth connection with my car. e.g. after I turn off my car with spotify playing. When I press the volume up button of my phone I expect to see the app still in control of music by allowing my to play the paused song. Instead the phone shows that no app is connected to play music. I have to restart spotify for it to play songs again.
3. Spotify doesnt not automatically start playing songs from where it had left off when reconnected to a bluetooth device like a car