The contact owns a 2007 Mercedes-Benz GL450. The contact stated that while driving approximately 50 MPH in the rain, there was an abnormal smoke odor inside the cabin of the vehicle. The contact stated that the vehicle then started filling up with smoke. The contact checked and became aware that the back of the front driver's seat was on fire. The contact was able to pull over and extinguish the fire with his hand. The contact sustained a little burn to his hand, but medical attention was not sought. The Fire Department was not contacted. Neither a Police nor Fire report was not filed. The vehicle was towed to the local dealer where it was diagnosed that the seat needed to be replaced. The vehicle was not repaired. The manufacturer was contacted but no assistance was provided. The approximate failure mileage was 59,050.