A dream is the only place you will find it! :laugh: I have a tank that goes on in the place of the front light, kind of a fake number plate that holds gas.... holds about a half gallon too.... I doubt I will ever use it, but you never know....
you could build a side car for your bike.....but instead of mounting a seat there you could mount a 55 gal. drum,....or take it to the next level with a 275 gal. oil tank..with that kind of tank you could ride down here to southern Maine ride my trails with enough gas to get back home..
I've seen a system where you have what looks like a square tank mounted where the tool bag go's on the rear fender,only about a gallon though. Mailer (sp) makes gas bottles that mount on crossbar, about .8 gallon I think. Puts you right up there with that IMS tank for about 1/20th the cost.