I STARTED TO BACK OUT OF MY DAUGHTERS GARAGE AND FELT THE TIRE HIT SOMETHING. I DIDN'T WANT TO BACK OVER IT SO I PULLED FORWARD, PUT THE VEHICLE IN PARK, OPENED THE DOOR AND STARTED TO GET OUT. I GOT ONE FOOT ON THE GROUND AND THE VEHICLE TOOK OFF IN REVERSE. I WAS THROWN BACK INTO THE SEAT. THE DOOR BEING PARTIALLY OPEN HIT A BOX WHICH FLUNG THE DOOR COMPLETELY OPEN. THE DOOR CLIPPED THE GARAGE DOOR JAM AND PUSHED THE DOOR INTO THE FRONT FENDER DAMAGING IT AND THE DOOR. I'M NOT SURE IF THE VEHICLE ACCELERATED BUT MY WIFE WHO WAS STANDING OUTSIDE SAID SHE WONDERED WHY I WAS BACKING OUT SO FAST. I GOT THE VEHICLE STOPPED JUST OUTSIDE THE DOOR AND SHUT IT OFF. IT ALL SEEMED TO HAPPEN PRETTY FAST.