[sisforsurfing]

Not a bad first try at all! It looks like you have a good start on building an eye for composition. #4 is good.

One rule of thumb I have for shooting cars is that unless it's for some wide-angle effect, I get as far away from the car as possible and use as much lens (zoom) as I can. Cars are big, so shooting close to them makes it hard to "separate" them from the background.

The only other real tip is worry most about good light. If it's nice golden light, usually after dawn or at dusk, go shoot. Don't expect much if the light is bad, everythign will look flat.

Word of warning that shooting black cars is harder than shooting light cars since they absorb more light, but that'll just make it easier when you shoot a buddy's silver car. Take lots of pictures!