sanded mine with 600, 1000, 2000 and then swirl and haze remover followed by polish and then wax ... lol, too many steps, but it looks awesome! Also did the same to take the faded factory decal/lettering off the panel between the tail lights and it looks perfect; well, except for a slightly milky looking area in the factory plastic that can be seen if you're really close. Will probably do it to my taillights when I get a chance 'cos there's some overspray on there.
Tested this procedure on the wife's Focus first (did the headlights) and they went from yellow/scratched to brand new looking.

