Talked to my old team and to the best of their knowledge, the shots from the can inside the car are real, non-rehearsed. Everyone but the salesman was in on it at the dealership. The shots from outside the car where the car goes over the ramps and such are probably not Gordon, but a stunt driver doing those things as "add ins" for the video.
In any case, very cool, and I'm sure Pepsi is happy with the results they are getting.