Ever wonder where the folks in all those post-apocalyptic shows get all the gas to drive around so much? I used to think it was stashed in one of the giant plot loopholes until the Mercedes-Benz Ener-G-Force closed that big narrative gap. This rugged vehicle collects water on its roof and converts it into electricity to power the rig via a hydrogen fuel cell. With one of these you could drive forever, even if there's nowhere left to go.