are you using a DSLR of point and shoot camera.
the joy of DSLR is that you can control everything individually, so for these shots i set a slow shutter speed (1/80 to 1/150 sec) and then let the camera meter the aperture and iso.
i generally auto-focus the camera where i think ill get the best pic of the car, then strafe and shoot continuously, and hope a good one comes out. haha.
ill post up a series of shots for you later.