Help with vector tracing

http://img519.imageshack.us/my.php?image=helpuz4.swf&width=1280

As you can see I’m having some mayor problems with the wheels. I cant get any of them to look like an actuall wheel. I also dont know how to make the side work since I decided to take the rearview mirrors off.

I’ve also been thinking of how I am going to color this. Is it easier to lay a ground color and then put see through colors above that or to trace all color changes and then color after that?

This is my 2nd attempt to trace something like this =) the first one I gave up with becouse of the coloring.

If anyone know a good tutorial that would be awsome =) thanks alot!