I like the last one with the tire wall in the background, but like the first two it just seems the car is very centered in the frame. I feel I need to look more to the left, but it is too limited and the dead space behind the car is is not adding anything for me. Overall nice panning shots with good wheel movement and the car bodies nice and sharp.
I don't see a problem with a crop on a sports shot just to keep everything in the frame, but like on the last shot a crop could take out the wall and that is what gives me a sense of place on the track.
Looks like Laguna Seca, never made it up there while living in LA. Thanks for posting, I'm sure it beats watching these cars putt around town.