It could be my laptop monitor but the first three look a bit underexposed.
Interesting frame on #4.
If you'ld like to bring a little more focus to the car, try a larger apature to blur the background a little more. (or get a lens baby if you're feeling really experimental and adventurous :))
You're headed in the right direction. Keep shooting.
If you need ideas, certainly check out your favorite car mags and imitate some of their shots paying attention to the lighting, background, angle, sky, composition lol.
