Looks like they have the worst special-effects team of the whole business... Or they have been paid by Audi to say crap like that.

When you want your car to go on the roof, you just put a special hydraulic or pneumatic arm (piston...) under it with a button. Press the button and the cars jumps on the roof. With that, you can make a double-salto on a flat road with a Carrera GT.

To see that in action, just watch the scene of Casino Royale when the DBS jumps in the air for no apparent reason when Bond tries to avoid Eva Green.