http://www.break.com/index/awesome-car-chase-at-disney-world.html
To make the cars light enough to do the jumps....they are using fiberglass shells and motorcycle engines for quick acceleration .
I remember seeing something about this on tv. The cars are obviously all specially built for it, and as someone mentioned on the page, when the red car goes over the ramp, he is actually facing forward. Before that when they disappeared for a few seconds, a different red car comes out to do that stunt. Pretty freaking cool.
Given the title I thought it was going to be the real thing, something along the lines of a Disney employee snaps.
Saw this last week at Disney.....very cool. There are actually 2 red cars used in the stunt. One has the driver facing backwards. When one red car goes behind the buildings, the other one takes over for the scenes going backwards.