I don't think this has been brought up here before,
On my glove box door and door panels, I have some light scratches caused by duffel bag zippers. They are very noticeable.
I've tired different way of trying to clean or cover up the scratches.
The best way that I found to clean it up is to use ordinary paste black shoe polish. Once you rub it into the scratches, 99% of the scratches are gone and cannot be noticed. It blends in nicely.
Once the polish is on, it does not rub off on your hands and it also seems to be long lasting. I covered up some scratches last spring and it still looks good.