TL* THE CONTACT OWNS A 2007 MERCEDES S550. THE CONTACT WAS STOPPED AT A TRAFFIC STOP AND NOTICED SMOKE COMING FROM UNDER THE HOOD. THE CONTACT STOPPED IN A PARKING LOT AND NOTICED FLAMES WERE INSIDE THE GRILL AND BEHIND THE PASSENGER'S SIDE HEADLIGHT. THE FIRE DEPARTMENT WAS CALLED AND A FIRE REPORT WAS FILED. THE VEHICLE WAS TOWED TO AN INSURANCE YARD FOR INSPECTION. THE FIRE CHIEF ADVISED THE CONTACT THAT THE FIRE WAS CAUSED BY AN ELECTRICAL FAILURE IN THE HEADLIGHT UNIT. THE VEHICLE WAS NOT REPAIRED. THE APPROXIMATE FAILURE MILEAGE WAS 51,000.