My 2004 A6 Quattro 3.0 constantly displays on my dashboard that the rear driver's side door is open. It started off only doing it randomly on really hot days, but now it displays the door being open just about all the time. I've had to turn the dome light switches off because all the lights were staying on thinking the door was open even when the car is parked and turned off. The window, lock, and floor lights on the door all work. Please help...