Modern DSLRs and CSCs have a number of focus zones to call upon, but most of them aren’t needed when taking motor sports images.
By limiting the focus areas to only the central zone the camera won’t be interested in the background or foreground, only the subject. By keeping the subject in the centre of the frame not only will your framing be much improved, but you’ll have enough room around the subject to track it.
Try to move as much as possible also. We understand that this may not be convenient in many cases, when photographin car racing but try not to get stuck in one position. Although you can vary the angle you shoot from to some degree, there’ll still be an amount of similarity between shots.
You’ll also give another photographer the chance to take a few images from the same location. This will help to get a wider variety of shots, especially as different techniques will be needed at each position. Try to look out for obstructions when scouting a new location, as the likes of tall grass might not be immediately obvious when viewing from further away.