That part is actually made out of aluminum (or some other light metal), covered with a plastic coating. Can't really be repaired, unless you use bondo as 91LSMAN suggests. I replaced mine a while back, cost me around 80 bucks. It is held on by plastic clips which will more than likely break when removed, so order those as well if you plan on replacing it. They come in black, so you would have to paint yours to match.