An it can either use a Premium Rdio account or the one that comes with the car, both suffer from a bug where only Rdio stations can be played which is OK if you don't want to listen to a specific track / album as it's near impossible to get exactly what you asked for.
Also, the 3G connectivity in the UK is patchy at best, I have no idea why Tesla didn't go direct with a 3 and 4G capable option, it's not like it would have been a big cost in the price of the car.