Have a 2006 Mazda 3, it has been cared for well, but over time the headlight covers were showing their age. Have tried various polishes and even 3000 gr. sandpaper. But the slight yellowing seemed to remain. So tried armor all headlight wipes. They worked pretty well, you can see the yellowing on the cloth coming off. Now it's not perfect, but it did work in making the covers look almost new again. Followed up with some liquid flitz polish and some wax. All in all a good simple process. Cheers.