Everything but the engine, and the driver who's gunning it, wants this car to roll back down the hill. Gravity in particular. The key here is momentum, which is a function of mass and velocity. Basically, the driver needs to get the car flying before hitting that slope. Once he starts heading up, he probably downshifts, since he wants to keep his RPMs as high as possible as the car starts to climb, and retain some of that momentum. The tires on the car are probably deflated slightly, too. This increases the surface area over which the weight of the car is distributed, and makes it a little less likely to sink into the sand. Just how steep is the slope? Our viewing angle tricks things up a bit. You can see once the car nears the top that the slope's not quite as vertical as it looks from a distance.

Towards the top, the fact that the driver flips, then rights himself, is absolutely amazing. There's clearly a mixture of luck and skill involved here, but he's helped in his descent by the fact that most of the mass, and the momentum, is carried up front. The car wants to go down head-first.

Think he tried this again?—Gregory Mone