AT APPROX. 4:45 PM 12/14/06 WHILE IN PORTALES NM. I WAS CHECKING THE TRAFFIC BEHIND ME WHEN I HAD THE CLEAR TO BACK UP. SUDDENLY MY VEHICLE ACCELERATED AND WENT INTO A BACKWARDS SPIN AND STOPPED AFTER IT SIDE SWIPED A TRUCK WHICH WAS ORIGINALLY PARKED BEHIND IT AND FACING IN THE OPPOSITE DIRECTION. *JB