I've tried reporting a bug where on a 2016 Mercedes GLA if you're playing MP3s from a USB stick the car will remember the track to play but nothing else about it, so after coming back the same track plays but with the wrong name, wrong album art, etc etc. It's literally impossible to. The dealer said they have no way to do that except for just flashing my car with a newer FW and hoping it fixes it(it didn't), messaging Mercedes UK yields no reply, posting on their official forums yields no reply.....I just gave up after a while.