I'm guessing since you have your own Premium Account (not included or paid for by Tesla like the Slacker account), then I think you can create your own playlists for a specific artists... You have ultimate control as a Premium Account.
And it works well if you have Premium. Brings all my playlists over, basically functions as the normal app version. Can sometimes time out, but usually flicking to another source and back again will fix any issues. Don't think you can download songs or anything (not tried) or specify quality of the songs etc.