You're getting better.
Just remember, when using brightness/contrast, don't overdo it or it'll look bad.
Another thing, make sure that the darkest part of your image is completely black, or they'll appear too bright and flat (take for example the 2nd BMW shot, in which the darkest part of the image is grey). It's all a matter of experience, just practice.
Take one image you like, edit it in different ways, see which style you like best and move on from there.