Just used my Q7 for the first time in over a week (Vacation). Although when I first put it into reverse the rear camera came on, subsequent, many subsequent attempts putting the car in reverse failed to put the camera up on the MMI screen. I had been storing radio stations right before that. Does anyone know if I might have accidentally deactivated the camera somehow? I'd like to make sure so it doesn't happen again. After turning the car off and on three times, and using reverse gear, the camera did come back.??????????