I agree with the others, but I also know that "real" automotive parts can have seams and a rough, unrefined look to them. IMO, if you remove every seam, and clean up all the parts too much, you lose a depth of realism. I, like others have been around cars my whole life, and if I don't know how "finished" a part is suppose to look, I find it in pictures, internet, or auto parts store.