REAR TAILGATE WAS LEFT OPEN. STARTED CAR AND NO WARNING THAT TAILGATE WAS OPEN WAS GIVEN. STARTED TO MOVE CAR INTO GARAGE AND OPEN TAILGATE STRUCK GARAGE OPENING. DAMAGE IN EXCESS OF $1000. NO WARNING IS GIVEN UNTIL CAR EXCEEDS 6-7MPH!!! THIS IS A SAFETY ISSUE, AS SOMETHING IN THE BACK WOULD ALREADY HAVE FALLEN OUT BEFORE ANY WARNING.