ok so i have a dented rear quarter because some dumb lady backed into the side of my car so i figured id practice rolling a fender (since it will be repaired incase i fukk it up) ..with a heat gun and rubber mallet....boy am i glad i used a bad fender....lots of cracked paint and it looks misshaped from the side there are little indents where i make the cuts in the lip to bend them up.....anybody know why this happened?