Some bluetooth audio systems have a very high delay. My car’s like 2 whole seconds. I use my android’s display to play movies for the kids when traveling and use the car’s audio system for sound, but the audio is very late and it’s annoying. There should be an option to delay the video in a customizable way so that the audio appears synced up.
Separate audio/video controls would probably be overkill. A simple audio OR video delay slider that goes -/+ 5 seconds is probably all it takes!