Can you not find a gas station within 275 miles? :p (Sorry, had to go for it)

I heard one time that owners of earlier model Mustangs were letting them go because the tank was under the trunk and posed a serious risk in the event of a rear-ending. If you don't use the cargo area you could put it in there. Probably your best solution is carry spare fuel cans (eg jerry cans). That way, when you're getting low, you can just pull over, fill up, and be on your way. No more searching for a gas station, and you may even save money if your gas prices are lower than your destination's or those along the way.