jarledb: You are limited to streaming from one place with Spotify (well, if you do it from somewhere else, it will stop streams other places). So to be able to use Spotify at home and in the car at the same time, you would need two accounts.
This is strictly speaking true, but if you put Spotify on your phone to offline, then you can play (offline) playlists without affecting the playback on the other device.
I have around 10GB on my Windows Phone and it plays fine through Bluetooth in my Skoda. Usually have to start a playlist, but if you stop somewhere in the car and then drive off again it will normally automatically carry on playing. It does seem to depend on how much you do with your phone while disconnected from the car however.
