SUDDEN ACCELERATION: MY WIFE WAS TURNING THE CAR AROUND IN OUR DRIVEWAY. THE CAR STARTED ACCELERATING WHILE IN REVERSE. MY WIFE PRESSED THE BRAKES, BUT THE CAR WOULD NOT RESPOND. IT STARTED SLIPPING IN PLACE UNTIL IT HIT THE FENCE. MY WIFE CONTINUED TO PRESS THE BRAKE UNTIL THE ENGINE RPM RETURNED TO NORMAL. MY WIFE INDICATED THAT SHE HAD EXPERIENCE A SIMILAR ISSUE LAST WINTER WHILE DRIVING ON A SNOW COVERED ROAD, BUT THE ACCELERATION STOPPED QUICKLY. AT THAT TIME, SHE THOUGHT THE CAR JUST SLIPPED DUE TO THE WEATHER CONDITIONS.