The art of good body work isn't something you can learn by reading. You can read about it but it takes a lot of practice to do it correctly. Just remember that every time you strike hammer on dolly you are stretching the metal between which must then be shrunk. If you have an area tech school that has a body repair class I would strongly recommend taking it. If your hub caps are in resonably good condition I wouldn't touch them with your hammer & dolly.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.