Photographically I don't see anything significant about these pictures.
They look like pictures I'd see on Facebook of somebody who just got their new car, and did some quick snapshots on their camera.
Use basic photography theory and stuff into play.
Since you're not really "capturing a moment" with car photographs like these, you have to use composition to your fullest.
Rather than worrying about the backgrounds and stuff, think more into the car.
Framing is a nice for automotive photographs you should look into.
Use a longer lens, and shallower depth of field to start.
Try shooting in the shade, or during 'golden hour' or whatever you might call it.
I agree with what somebody else said with being different
But I think you should learn the basics before branching off.
I try to shoot cars, though I am not that great at it yet, or anywhere near a professional level.
http://www.thephotoforum.com/forum/general-gallery/279307-c-c-automotive-photographs-outdoors.html