Great pictures. Those really help. For one, I don't think that is oxidation. It looks like clear coat failure to me. Not much you can do for it. You can go after it with a machine and polish out as much as you can, but that area is never going to have an OEM shine to it again. Its pretty far gone. For a 99 that is terrible. He must have been parking under some seriously acidic stuff to get that bad so quickly. I've never seen a car look so bad so quickly.