I would reinstall that thing elsewhere.
Mine sits inside my car at the base of my winshield in the center and I get excellent reception 99.99% of the time.
I use a two small pieces of adhesive backed velcro to hold it in place. I also have attached a small metal washer to the base of the antenna, seems to help reception, but it is likely just me wanting to think it does.
Good luck on the scratches, I would think those could just buff right out.