I'm hopeful in the future iOS, Android, and automakers develop a new type of API for integrating the phone into the car. Currently CarPlay and Android Auto look like they completely take over the screen, with the option to exit and go back to regular car UI. The alternative that could be a better option is let automakers keep their UI, but open up an API where an individual app asks for permission to insert and integrate into the car's UI. So let's say for Spotify, they expose additional API information so the car can pull playlists, browse tab, search tab, radio, etc from the app. If any streaming occurs it will be over the phone's data plan and through Bluetooth or direct connection. On the vehicle side, like on the Tesla, it will insert a Spotify icon and render basic playlists/search/browse/radio, allowing it to keep its basic functions but allow the car to keep its UI intact. You wouldn't have to load the app on the phone, but in the car UI you click the Spotify icon to launch the app on the phone in the background. I know someone made a Spotify website that you go to in the car's browser that controls Spotify on your phone, so something similar to that but integrated into the car's UI. If Tesla has a deal with Slacker and TuneIn then this might not be possible/allowed, plus Spotify would have to give up its unique UI design and allow the car to dictate how everything shows up. Every other music app could do something like this. It shouldn't put too much CPU cycles compared to doing a full Carplay/Android Auto thing, possibly.