King of the Road Warriors

When Paul Watson drives to work at Yatala, on Brisbane's southern edge, he rides high—and not just because of his vehicle's 37-in. wheels. He enjoys the double-takes people give his khaki and brown car-or-truck-or-is-it-a-tank: "They'll come up and say, Wow, that's awesome," says Watson. But the biggest lift comes from driving something that once existed only in his imagination: "To drive it down the road and think, 'We built this'—that's a real buzz."

Rhino Buggies, the firm Watson runs with his son and three staff, makes cars that out-hum the Hummer. They can drive over boulders as big...