I really like the layout on the first photo. I think I will try something like that next time I shoot. Any tips if the car has more of a rear bumper and if it's farther from rear wheel back to the bumper? Would the shot not be as cool if it was like that?
Obvioulsy a closed wheel car is going to look different from this angle. But the key is capturing something the viewer is attracted to.
If everything you shoot is from eye level, then that will be exactly what everyone sees when they are walking around without a camera. Do something different if you want your images to stand out.
I'm too old to lay down on the ground for those shots so I have learned to shoot bending over with the camera as low as ground level. It just takes some practice, the right lens and enough open area around the car.
Shoot some from eye level, chest high, waist high, knee high, on the ground and even with your hands extended above your head.
A nice sky or background is another item to keep in mind when shooting low. Quite often you will get power lines and/or poles in the shot but those are easily fixed in post.
Another thing to keep in mind is your reflection in any chrome. Try to minimize it by choosing the right angle but you can fix it in post if your are doing a large print for the client.
The most important thing to remember is to shoot to please yourself FIRST!
Here are few closed wheel cars from a low perspective.
(as usual - all comments - JMHO)