I agree that a lot blur add to the motion and I usually do capture the speed through panning shots in mid exposure shots like this one:
http://i131.photobucket.com/albums/p...Picture280.jpg
http://i131.photobucket.com/albums/p...Picture156.jpg
However, occasionally, I like to freeze everything when shooting motorsport, to really capture the car and the moment...call me akward, but its true
