[Nissan Mike]

You're gonna have to go to a pressure washer at a self car wash. Put on a bathing suit and goggles (I'm not joking), and lay underneath and start spraying. It will take a longgg time!

Oh Crap,I just got an image of a guy laying underneath his truck in mud,wearing swim goggles and his wife's "bathing suit" at the car wash with everyone watching!
Maybe swim trunks instead? lol