There's more to a Mustang than just a Mustang! I've taken everything off this car with my own bloody knuckles and put it all back like I wanted it, mostly... and mine is a step more from that, it's a 4cyl that will run circles on most factory cars, and can corner too! (not with these wheels though)
You should get Boy a mustang, a really really crappy one, with a 2.3n/a engine, and hahve him eco mod it! I know a guy with a 2.3 notch from '88 that got 41mpg on a recen 600+ mile road trip. It would be a great opportunity to learn autos and they are dirt cheap too!