What world are you living in where Apple Music (subscription or just the app with your own tracks) or something like a paid Spotify subscription don't give you this? We can ignore the subscription and look just at the Apple Music app which supports DRM-free music without issue, has no commercials, no promos, no licensing issues. You are describing an experience that everyone can have today, using CarPlay, using Apple Music or any other music playing app that has CarPlay support. At worse just skip CarPlay and Bluetooth or Aux-in to your car (with the dongle).