There are many ways to capture motion. The most common is to pan with the car. Pick a spot on the track where you think the car is going to be and manual focus there (you can auto focus too, but I like to eliminate that variable unless the driver is missing the line). I shoot around 1/500 to 1/800, depending on speed, DOF, etc. This slightly slower speed creates motion blur without being too much. By panning you are trying to move at the same speed as the car and this helps to freeze the car, but since you are moving across the background, the background blurs. Shoot tight and crop a ton. The key here is to capture "the shot" and unfortunately you will create a lot of throw away shots, but that's the price you pay. I try to shoot low and I almost never use a tripod or monopod, but that may be personal preference. Shot with telephoto around 200mm (which is longer with digital) Example: