2000 Audi Quattro GASOLINE LEAK

ENGINE LIGHT HAS BEEN ON FOR A COUPLE OF MONTHS BUT I WAS TOLD IT WAS THE CAT CONVERTER AND NOT TO WORRY, VERY EXPENSIVE AND TOLD CAR MAY HAVE TWO CAT CONVERTERS. FAINT GASOLINE SMELL FOR A WEEK OR SO AND NOW A GAS LEAK ON THE DRIVEWAY UNDER THE REAR PASSENGERS SEAT AREA. ALSO, CAR ENGINE HAS HAD SOME SLIGHT HESITATION IN TURNING OVER AND THE LAST TIME IT WAS STARTED IT HESITATED AND I SHUT OFF AND AT THAT TIME SAW THE GAS ON THE DRIVEWAY AS IF IT HAD BLOWN OUT WHEN CAR WAS STARTED. I LIVE ON A PENNINSULA IN MAINE AND DO NOT HAVE EASY ACCESS TO QUALIFIED, TRUSTWORTHY MECHANIC. I REALIZE IT WILL NEED TO BE TOWED INLAND AND WOULD LIKE TO KNOW HOW SERIOUS THIS PROBLEM COULD BE OR IF IT IS A SOMEWHAT SIMPLE REPAIR(S) THANK YOU.