My 96 GTS (heads, cam, exhaust) had a bottle bolted to the spare tire cover (!) - I took that out as soon as I saw that. Seems everyone has one or two bottles inclined over the spare tire. So the only real option would be some kind of short, fat bottle to tuck by the fenders - perhaps two of them, one on each side. Even a spherical bottle might be efficient if they are available. Or maybe a manifold of multiple motorcycle bottles (filling = UGH!) But I haven't been able to find any pics of layouts that allow access to the spare. NOTE: Still have to save some space for a methanol injection for supercharger if I go that route too.