Headlights are often neglected because people figure that they are getting washed with the rest of the exterior – there’s no need for additional maintenance. However, the headlight lenses are just as susceptible to debris and UV degradation as the paint, maybe even more so.
Headlight lenses are made of polycarbonate plastic in order to make them impact resistant. This plastic is functional, but it can cloud over time as a result of UV exposure. As the lens clouds, it restricts the amount of light that can pass through the lens which causes reduced visibility. The good news is that this problem is easily corrected with a common household product… Toothpaste!
Spray some window cleaner onto the headlight and use toothpaste as a mild abrasive to remove the oxidation buildup on the headlights. It take a little bit of elbow grease to get the job done, but keep spraying the window cleaner, to keep the toothpaste from drying, while applying the toothpaste in a circular motion with a clean cloth. Once all the oxidation is removed, rinse off all the toothpaste with water. Spray some window cleaner to make sure all the residue is gone.