Not really possible. The actual race was 3hr49min, and 49min of the commercials were shown during the race for a total 3 hours of broadcast race time.
Speedvision is showing this in 3 hours INCLUDING commercials, so there's no way they are showing more than a little over a couple of hours of 'enhanced' racing.
I can't stand NASCAR, give me F1, CART, LeMans, but I'm probably going to watch some parts of this just to see what they do 'enhancement' wise. This could be the future of race replay broadcasting.
I'm guessing just alternate angles, more in-car shots, more scanner radio, and maybe some replays of wrecks for the bloodthirsty fans.