I WAS DRIVING MY CAR, A 2004 VW PASSAT GLS, TO WORK IN THE MORNING AND HAD THE DRIVER'S SIDE SEAT HEATER ON. ABOUT 2 MILES INTO MY DRIVE I COULD SMELL THAT SOMETHING WAS BURNING. AT FIRST I THOUGHT IT WAS SOMETHING BURNING OUTSIDE, SO I ROLLED THE WINDOWS DOWN TO SEE IF THE OUTSIDE AIR SMELLED OF SMOKE. THE OUTSIDE AIR DID NOT SMELL OF SMOKE, SO I QUICKLY STARTED THINKING OF WHAT ELSE COULD BE BURNING. I ALSO HAD THE CABIN AIR HEAT ON, SO I DECIDED TO TURN THAT OFF AND ALSO TURNED MY SEAT HEATER OFF, WHICH IS WHEN I NOTICED SMOKE COMING UP FROM THE DRIVER'S SEAT. I IDENTIFIED THE LOCATION AS THE LEFT PART OF THE SEAT BOTTOM AND SAW THE BURNING AREA, WHICH WAS CLEARLY BEING CAUSE BY A HEATING COMPONENT OF THE SEAT HEATER. I WAS TRYING TO PUT OUT THE SMOLDERING AND SMOKE WITH MY HANDS. I COULD TELL THAT MY LEATHER SEATS WERE STILL SMOLDERING/BURNING SO I PUT WATER ON MY HANDS FROM A WATER BOTTLE THAT I HAD NEARBY TO COOL THE LEATHER AND PREVENT FURTHER SPREAD OF THE SMOLDERING. NOTE THAT THIS WAS ALL WITHIN APPROXIMATELY 10 SECONDS, AND I WAS DRIVING. THIS IS A HUGE HAZARD FOR WHICH VW SHOULD BE HELD RESPONSIBLE. *TR