When you're just walking around and you see a car, that is the exact (or very near) angle you see it from. That's the angle you see the whole world from: 5-6 feet up. Getting an overhead view, or a bug's eye view will give you a whole new perspective on the world.
Also, don't center it. Usually when I try to compose something, I find that, when in doubt, use the rule of thirds. Then check the LCD and try different compositions. Try putting that headlight in the bottom left or top left third next time you shoot a car. I find that it usually gives a very intimidating look.
As for things you can still fix, the whole picture is slightly dark, and it needs contrast.
Five-six feet up=bad.
Rule of thirds=good, usually.
Contrast=good in today's world, but don't overdo it!
Keep shooting