Four-wheel-drive trucks compete in many types of motorsports where no car would dare show its face. To realize the ultimate potential of a competitive truck, many off-road activities are fitted to four-wheel-drive trucks to race on mud, rock and sand. These trucks are shown in action: there's nothing like four heavy-lugged tires clawing for traction and throwing up clouds of dirt and rocks, "Tough Trucks" navigating jumps, water and obstacle courses,...