UPON REFULING MY AUTOMOBILE FULL I COULD SMELL A STRONG ODOR OF GAS FUMES. EARLIER THAT DAY I HAD AN IMPACT OF MY TIRE OVER A CURB. GAS FUMES COULD BE SMELLED NOT SO MUCH ON THE OUTSIDE OF THE AUTO BUT INSIDE WITHOUT ABATEMENT. UPON INSPECTION BY MERCEDES BENZ OF STOCKTON CA IT WAS DETERMINED A FUEL LEAK WAS PRESENT WITH THE CUSHION THAT SITS ON TOP OF THE FUEL SYSTEM WAS SOILED/STURATED UNDER THE REAR PASSENGER SEAT OF THE CAR. PICTURES TAKEN SUGGEST IT HAD BEEN WAS ONGOING POSSIBLELY FOR YEARS. THEY SUGGESTED HEAT CONTRIBUTED TO THE UNIT-SEAL CORROSION AND ITS SURROUNDINGS. IT IS NOT CLEAR WHY MY RIGHT REAR IMPACT WITH A CURB BROUGHT THIS ALL TO MY ATTENTION. HIGHLY COMBUSTIBLE SITUATION THAT WAS CLEARLY NOT DETECTED WITCH IS NOT COMPLETELY UNDERSTOOD THE SAME DAY I HAVE AN IMPACT TO THE RIGHT REAR TIRE JUMPING A CURB THEN GOING BACK OVER IT TO UNLODGE THE TIRE & ROCKER MOLDING FROM THE CURB & REFUEL I SMELL GAS FUMES. HIGHLY DANGEROUS USING PLASTIC SECURE GAS EXCHANGES ON SOMETHING PEOPLE SIT ON? HAS SIMULARITIES IN OTHER DRIVERS. NOT SURE WHY THAT DAY THE SEAL (PLASTIC) RUPTURED (AT PLASTIC LID)