2005 GMC ENVOY DENALI W/37,800 MILES. ON SEVERAL OCCASIONS, WHILE COMPLETELY STOPPED, THE VEHICLE WOULD SLIGHTLY LUNGE FORWARD AS IF GOING TO ACCELERATE ALTHOUGH THE BRAKE WAS ENGAGED. WHEN LOCAL GMC SERVICE DEPT. WAS CALLED BY OWNER TO INQUIRE ABOUT PROBLEM, SERVICE TECH SAID HE HAD NO REPORTS OF SUCH SITUATION. THE SURGE HAPPENED AGAIN ON 10/31/08 AND THERE WAS A PASSENGER IN THE VEHICLE WHO ALSO EXPERIENCED THE SENSATION. ON 11/17/08 WHILE AT A COMPLETE STOP, AFTER TURNING WHEELS SHARPLY TO THE RIGHT TO GO AROUND A ROAD EQUIPMENT VEHICLE IN THE PARKING LOT, UPON REMOVING FOOT FROM BRAKE, THE DENALI LUNGED FORWARD ENOUGH TO BUMP THE TIRE OF THE EQUIPMENT VEHICLE AND THEN IT ACCELERATED AS IF THE CRUISE CONTROL WAS ACTIVATED. THERE WERE NO BRAKES WHEN AN EFFORT WAS MADE TO STOP THE VEHICLE. STEERING OF VEHICLE WAS HARD DUE TO POWER STEERING FAILURE . VEHICLE JUMPED UPON A CURB, DRIVER FORCEFULLY TURNED STEERING WHEEL TO AVOID HITTING A BRICK BUILDING AS ACCELERATION WAS STILL ONGOING. VEHICLE CRASHED THROUGH A STEEL GARAGE DOOR AND CONTINUED UNTIL IT CRASHED INTO A RETAINING COLUMN AT WHICH TIME THE MOTOR WAS TURNED OFF. THE IMPACT OF THE COLLISION COULD BE FELT UP TO THE SECOND FLOOR OF THE BUILDING. THE DRIVER WAS WEARING A SEAT BELT. THE ONSTAR SERVICES DID NOT INITIATE RESPONSE TO DRIVER DESPITE THE FACT THAT THE FRONT BUMPER OF THE VEHICLE WAS NO LONGER ATTACHED TO THE VEHICLE, NOR DID THE DRIVER AIRBAG DEPLOY UPON IMPACT. VEHICLE WAS TOWED AWAY FROM THE SCENE. DRIVER