OUR 2007 CHEVY TAHOE HAD BEEN DRIVEN FOR ABOUT AN HOUR AND THEN PARKED FOR APPROXIMATELY TWO HOURS. UPON STARTING THE TAHOE WITH COLD ENGINE AND PULLING AWAY FROM THE CURB THERE WAS AN IMMEDIATE SMELL OF SOMETHING TOXIC COMING FROM THE AIR VENTS FOLLOWED BY BLACK SMOKE FROM THE ENGINE COMPARTMENT. THE VEHICLE WAS STOPPED AND TURNED OFF AND LESS THAN A MINUTE LATER THERE WERE FLAMES EMANATING FROM UNDER THE HOOD AND WITHIN A COUPLE OF MINUTES THE HOOD WAS BLOWN OPEN AND THE ENTIRE FRONT OF THE CAR WAS ENGULFED IN FLAMES.