Is it on the top side of the tips or the bottom? Can it be seen when on the car. ? Any pics of the scratches ? Are they deep scratches ?
Back when i had my E39 with the stock tips, i had one that was badly scratched: I used emery cloth and ALOT of elbow grease to basically sand through the scratch then progressively polish by going with lighter and lighter wet sand paper...was a huge *MESSY* chore, especially when i realized i had three more to do to make them all match!