I'm no expert on this, but, the engine and trans are mounted solid and the rear end has to move up and down. Hooking the trans directly to the rear end sounds like you'll be snapping the tail off the trans first bump you hit. You'll have to have some type of driveshaft with u-joints. As far as is it possible to mount it behind the drivers seat? Yes! In drag racing they have wheelstanders that do exactly that. Anyway, it can be done but there's alot of thinking you need to do before hand. Good Luck!