P100D used to be about $280K AUD on road (about $190K USD), that is why we get so peed off when things don't work.
Even if you pay $10K for a car, you should be able to listen to your music and the music should resume when you get in the car. Playing the music you own is really the most basic feature you can have in a car.
I used to own a 2007 Mercedes E550 (it was a super awesome car to own) with an ancient version of Mercedes' Command interface. In 2007, for all the antiquated Mercedes technology in that car, it could play my entire 220GB lossless music collection and resume music playback flawlessly and instantly via the iPod interface.
It's quite puzzling how my car from the future is having such a hard time resuming music when even a 2007 Mercedes E Class could do this flawlessly with the exact same music collection.