To be fair, car companies that design for both left- and right-side steering have enough differences in parts to worry about, so it makes a modicum of sense to only have one design of gas tank and rear body panels.
If you sell more cars to Japan and Australia than to the US, it is probably smarter to have the gas filler on the right. Some models of Ford are huge in England, so those models may be excused for the right-side filler.
But for here in good old USA, that right-side filler is indeed a pain in the bupkis.
