That's pretty impressive rust; I'm sure the reason the tank was rigged like that is there couldn't have been much structure left to strap a tank in the conventional location. But I'm not surprised that car is from Minnesnowta, I'm more surprised that it's got enough metal left to move down the road and not disintegrate after so many years.
I think my personal "WTF" moment was the guy I saw pulled over on the Ohio turnpike years ago driving some older GM boxy RWD sedan thing - I couldn't identify it because I was driving the opposite direction, and the entire front clip was missing - the only things forward of the cowl were the frame, suspension, engine, and the radiator support (it did have headlights...) I assume that there was wiring there as well... can't imagine anyone thinking that it was a good idea to try to drive that on the turnpike, but I guess my standards are higher than some.
nate