I PARKED THE VEHICLE AND LEFT IT RUNNING WITH MY MOTHER IN THE CAR WITH HER SEAT BELT ON. AS SHE WAS SITTING THERE THE VEHICLE ROLLED FORWARD ON ITS OWN AND HIT A FORD F150 PARKED ACROSS FROM MY VEHICLE CAUSING DAMAGE TO MY VEHICLE AS WELL AS THE TRUCK. I FILED A CLAIM WITH GMC AND THEY HAD SOMEONE COME TO MY HOME AND RUN TEST ON MY VEHICLE AND WAS TOLD THEY COULD FIND NOTHING. AFTER THEY FINISHED THE TEST NY LOCKING MECHANISM IS NOT WORKING PROPERLY. *TR