SHOOT IN THE DAY (preferably the golden hour)!!!!!!! Nothing worst than shooting a white car at night with ambient light. But i like the fact that you are shooting with a different eye... Notice how your composition has to be altered by using a longer lens? I like these shots a lot better than your last shoots because they are much more dynamic. Try to shoot while laying on teh ground and from far away during the day, and you will make teh car POP. Mainly because the dof at your widest ap will be just enough to get the car in focus and the background will be completely blurred out.