Recently I did a deeper dive into how Slacker streaming works by doing research on this board, other discussion groups, emailing Tesla, and RTFM. Since I came across a lot of conflicting information out there, I thought I'd write what I found down all in one place. It may be common knowledge to many, but here goes. Note, this applies to a mid-2016 facelifted Model S with UHFS. YMMV. Our cars come with 4 years of free access to Slacker Radio Plus. According to Slacker this allows "...ad-free listening, unlimited song skips, complete song lyrics and mobile station caching. You'll also get the custom ESPN radio stations that you can personalize with your favorite teams, sports and shows!" There's no need to login in your car, but you can email Tesla for your log in credentials to use on the iPhone app, etc. It's pretty cool to be listening to a song on your phone, hop in your car and pick up where you left off. Email your VIN to Tesla to get your credentials. Your email has to come from the email account registered with your Tesla account. Your Tesla Slacker account is not upgradeable, but if you go out an purchase your own Premium account at full price, you can log in with those credentials instead and listen to songs on demand. If you click the Sign In button at the bottom of the Slacker screen it takes you to a log in screen that has a "High Bitrate Streaming" checkbox. If you leave that checked Slacker streams 320kbps mp3. If you uncheck it the stream is 128kbps mp3. According to Slacker you can uncheck that if you're having buffering problems, but I've never experience buffering unless I'm completely out of LTE range anyway. If you want to listen to a particular song on demand just press the voice command button on your steering wheel and say "Play song whatever by whoever". Your Tesla will search Slacker and play that song if it's in their library (I've never had it fail to find one). It will set up a "song whatever" station and start playing related songs after your requested song is over. You can't go back and repeatedly request the same song, Slacker will just take you to the newly-created station that's playing related songs, but if you wait a day or so you can request the same song again. There must be a minimum waiting period to request the same song over again. That's what I found out. I hope it's informative to some people. As someone who has never invested in a streaming account before I've been very impressed with what Slacker has to offer, all completely free of charge with my Tesla!