VEHICLE WAS GOING 65MPH. CONSUMER WAS TRYING TO BRAKE TO SLOWDOWN, AND IT WOULDN'T SLOW DOWN. EACH TIME CONSUMER'S FOOT CAME OFF BRAKE, VEHICLE SPED UP. CONSUMER PULLED OFF ROAD, AND COULDN'T TAKE IT OUT OF DRIVE. VEHICLE RAN INTO SOME GRAVEL, AND THE SPUN BACK END AROUND. VEHICLE WENT OVER A 100FT. RAVINE, TAKING OUT 2 TREES, AND LANDING ON SOME ROCKS. UPON IMPACT, AIR BAGS NEVER DEPLOYED. GENERAL MOTORS IS SENDING A INVESTIGATOR OUT. *AK