It's easy to see something like this U.S. commercial for the Nintendo 3DS's upcoming Mario Kart 7 game, and assume all the neat stuff here is done in post-production, with everything but the actors themselves CG-d.

While that's true for the effects and objects floating around the course (e.g. Cheep-Cheeps, item boxes), the carts themselves and the stunts were in the original film, according to these clips I came across in Drivers Inc.'s Vimeo account.

The videos below show that the stunt driving team worked with the wacky drivable carts that look just like what you see in the commercials, and set up a scary double-crane and ramp setup to shoot a vehicle grabbing some air.

I wish there were more of these clips -- really, I'd love to see a real race of the carts without all the fancy effects added in.