Not bad for a first try, as neilm said some "background issues" and the only nitpicking I would do and its not just of you but a lot of photographers in general, they dont have there own style or individualisim.

Try your own style of pics and dont just copy what you see in car magazines as some of these are quite poor. Dont forget a lot of post processing goes on after the picture has been taken. Good luck anyhow.