I have a free Spotify account but have specific randomised playlists set up so tend to just stream that via my phone (BT) to the Parrot's built in bluetooth music player. The Parrot's Market version of Spotify isn't the latest but it does do the job alright. 95% of the music I have is played back from the phone direct though. I do not use Deezer.
I have rooted the Asteroid btw, it's got Google Play Store on there with various other apps not avaialble on the Asteroid Market but are on Play Store.
Over all I am rather impressed with the unit. I have improved its multitasking performance by upping the allocated RAM to 2GB via a fast SD card and RamExpander app. I switch between Waze and Music/other apps often so it's nice having the faster response when doing all this.
If the future of the updated Android Auto model wasn't an unknown then I'd have not bothered with all the tweaking, but as it stands, I may as well keep this for a lot longer as everything just works fine.