First apply the cleaning solution to the provided disc and rub it on the headlight casings to remove oxidation and cloudiness. (It also will remove all the accumulated grime associated with highway driving, taking salty splashes at a coastal ramp and winter driving in the northeast that splatters road salt.) Next, spray the casings with the protective coating. Meguiar's says it protects them from further UV oxidation for up to a year. We'll let you know.