If a deuce-and-a-half doesn't hold enough bitchin' military surplus awesome for your vision of a dystopian future, perhaps you might be interested in the Gama Goat, an articulated six-wheeled amphibious machine designed to tackle the worst terrains of Vietnam.
One of the forgotten vehicles of US military history, the M561 Gama Goat was designed as a go-anywhere, do-anything vehicle after the standard military trucks of the era were deemed unfit for the South-Asian terrain. Powered by a bonkers Detroit Diesel three-cylinder 2.6-liter two-cycle inline three producing 103 HP, the Goat is an odd duck to start.
While it was terrible on pavement, it was nearly unstoppable out in the bush and given its 2900-lb payload it's able to move more than just basic supplies. The Goat's amphibious capabilities have mostly to do with its ability to float, but forward propulsion came from the six wheels so it wasn't exactly speedy. With its tough attitude and a face only a zombie hunter could love it could easily find a warm spot in our garage of insanity. [Wikipedia, Craigslist]