Yeah that deck lid is a right pain. You practically look at it and it gets scratches on it. I think we need to remove it and clear film wrap it or something. I've been wondering exactly what to do about it myself.
https://www.rpidesigns.com/shop/item.aspx?itemid=5419
Originally I was going to go with the ones from American Muscle but they required drilling into the car which I didn't really feel comfortable doing. Also these ones are fairly subtle. I have only installed the front spats though. Not sure...