Spotify is my fav- but In addition to Spotify, I wouldn't mind seeing other streaming services like Amazon Prime, Itunes, etc.. we should have more than one choice (or two if you include tune-in) for native streaming in the car.
SPOTIFY is 2014 the leading music streaming service worldwide with 24 million active users*! And the number is growing fast! It perfectly fits to a car like the TESLA - but why is it still not supported?? (* http://www.whathifi.com/news/best-music-streaming-services-2014-comparison-review)
This would be a welcome addition. It is easy to stream Spotify from our phones. However, the high bit rate streaming that Spotify allows (better than Slacker) is largely lost in transmission with Bluetooth. The difference (high bit rate natively vs high bit rate via Bluetooth) is noticeable, especially with the optional stereo upgrade.
This may have to wait until they upgrade to 4G however, since I don't think the 3G currently could handle high bit rate streaming.