Great stuff! I have a suggestion. Long time ago, when I was still building military stuff, I made a diorama including an abandoned VW Bug that was pierced with bullet holes. As you can see in the pic, there are dents where the bullets went in, to achieve that, just dremel them in with a round head (I have no idea how it is called in english, you know, all those fittings you have for a dremel, there are all kinds of things, one of them being a round ball on top of a stick) over the bullet holes. Make some of them just slight, others a bit deeper. Then paint the body in any metal color yo desire, let it dry, use maskol (you know, that pink stuff you buy in a hobby store, or latex) and just tap very small amount over the holes so that it sticks to the edge of the hole. I used a toothpick that I dipped in maskol, and just pressed it in each hole, when you take it out again, a small amount of it will stay on the edge, repeat when neccesary. After that paint the body. If you scrap the maskol off with a scalpel by pulling the mask, it will tear the edges, and the result is a genuine bullet hole that is as realistic as it can be!