DRIVER'S SEAT HEATER SHORTED OUT WHILE VEHICLE WAS BEING DRIVEN. THE EVENT OCURRED SO QUICKLY AND WAS SO SEVERE THAT IT BURNED THROUGH THE LEATHER SEAT UPHOLSTERY AND A VERY HEAVY PAIR OF DENIM JEANS I WAS WEARING ALMOST IMEDIATELY AND UNEXPECTEDLY. THE CONSEQUENCES ARE PRETTY MUCH OBVIOUS AND COULD RANGE FROM SEVERE BURNS, TO THE VEHICLE BURNING TO CAUSING A SERIOUS ACCIDENT BECAUSE OF THE SPONTANEOUS HAPPENING. NO RESPONSE FROM MERCEDES BENZ TO DATE.*AK