FOLLOWING A LINE OF CARS DOWN A CANYON ROAD AT 50 MPH. SPORT MODE STEERING TURNED OFF. CAR DRIFTED TO RIGHT SIDE OF ROAD. TURNED WHEEL SLIGHTLY TO THE LEFT, BUT CAR KEPT DRIFTING RIGHT. RIGHT SIDE WHEELS THEN WERE ON GRAVEL SHOULDER. TURNED STEERING WHEEL TO THE LEFT AGAIN. CAR TURNED 30 DEGREES TO THE RIGHT AND WENT AIRBORN OFF THE ROAD AND DOWN INTO THE CANYON, LANDING FLAT ON A PILE OF BOULDERS, BOUNCED OFF AND BECAME AIRBORN AGAIN, FINALLY STOPPING IN A TANGLE OF THICK BRUSH. UNDERSIDE OF CAR TOTALLY SMASHED. CAR WAS A TOTAL WREAK. DON'T KNOW WHY THIS HAPPENED. FELT LIKE STEERING LINKAGE SUDDENLY DISCONNECTED. *TR