There’s no question from this photo that the door-striker assembly was installed early on and painted body color. The upper bumper on the door has imprinted itself into the black exterior finish, exposing the gray coat beneath. Knowing that this car has just 213 miles on it, we can rule out any relation to body flex and it rubbing through the finish. It’s more likely some type of release agent used during the rubber-molding process caused the black finish to lift over the years. While it may not be a common occurrence with other cars, this Firebird literally sat with its doors closed for years at a time, so it’s certainly possible!