How to refinish window rock guard?

Look at the frame, they are usually either screwed or pop riveted at two corners. Take it apart. Then you can buy a piece of plastic or a sheet of fiberglas to replace the worn out piece. It aint rocket science and replacing it with a new piece is probably going to be cheaper, easier in the long run. A nice smoked piece of plexiglas would look good. Add a graphic of some sort and it could look better. Heck, Airstreams have used plexiglas on their front rock guard for years.