If you own a car with plastic headlamps (as opposed to glass), you’ll realize that over time it will start to turn yellow or opaque. This is caused by the dirt and impurities on the surface of the headlamp. Besides reducing the output of the headlamp, it also causes glare to oncoming drivers (more obvious on HID equipped cars due to the higher intensity). Cosmetically it will also look dull.
Before: Haven’t been cleaned for almost 4 years. Starting to look yellow and “foggy”.
The good news is, you don’t have to have them replaced to make them look new and transparent again. Just buy a bottle of headlamp cleaner. These can usually be found in hypermarkets.
The cleaner is very easy to use. Just make sure your headlights are clean and dry and dust free.
Apply a layer of headlamp cleaner with a clean cloth. Apply liberally. Rub lightly in a circular motion. After a few passes, let the cleaner dry on the headlamp without wiping it off.
After about 20 minutes, use a clean cloth and wipe away the dried cleaner. If your headlamps don’t look clear enough, repeat the above steps.
With enough rubbing you’ll be able to get the dirt off and have a clean and clear looking headlamp. Cheaper than buying new ones.