I finally got a chance to photograph some motor racing at a Skip Barber racing school held at Gratten Raceway in western Michigan (got a little chance to do a little racing as well). Capturing good car action shots depends on a number of things like access to great places on the track. One critical item, however, is trying to figure out the proper camera settings - particularly shutter speed. If you set a shutter speed to high, you'll stop the action. But the car will look like it's standing still with no sense of motion and speed. With too slow of a shutter speed, you'll get blurry photos which are no good for anything.
The top photo above, was captured using my Nikon D700 with 70-200mm VR lens attached. The camera was set in shutter priority at a shutter speed of 1/125 sec (aperture came in at f/20, with ISO 200, and -0.33 exposure bias). The VR setting on the lens was turned on using the active setting. The motion depicted in the spinning tires and wheels is due to the rather slow shutter speed. The blurry background and foreground are caused by the panning technique used to follow the car as it passed my vantage point while taking multiple photos at 8 frames per sec that the D700 is capable of capturing (with the vertical grip and pro battery attached).