Is that an original panel? It looks glossier then a factory panel and the grain doesn't look right. Maybe it's just the picture. I thought the factory panels were thicker then that too. It looks like the plastic is very thin in that area.
To tell you the truth, I don't think you are going to get that looking very good again. I hope I'm wrong. If that is a factory panel, it shouldn't be hard to find a replacement that's in decent shape. Sorry I can't be of more help.