Are you allowed to polish headlights?
In principle, the polishing headlights is not permitted. This is because the headlamp is a part-approved component that must not be structurally modified, otherwise it will not meet safety standards.
Nowadays headlamps are usually no longer made of glass, but of plastic and have an anti-scratch coating. If you try polishing plastic headlights, this layer will be removed and the plastic is attacked by the polishing agent and thus structurally changed.
What have you got to expect if you polish your headlamps?
Anyone considering polishing dull headlights by hand with multi-function products such as WD40, home remedies or repair kits should be aware that this may have legal consequences. Even if the luminosity of the headlamps is restored after using a polishing compound on headlights, these components no longer correspond to the condition in which they were installed and approved.
Consequences for road safety
Polished headlights can also be a safety hazard. Polishing may result in grooves or indentations forming on the headlamp. This causes the light to be refracted incorrectly so that oncoming traffic may be severely dazzled or one side of the road may be insufficiently illuminated.
If it is discovered after an accident that the headlamps have been illegally polished, the car insurance company may refuse to cover the damage.
The alternative: what can be done about dull headlamps?
Dull, scratched or yellowed headlamps should not be polished; you can replace them yourself or have them replaced in a workshop. Even if changing the headlights is initially more expensive, you will save yourself a lot of trouble and possibly also costs if you are found to have polished headlamps at the main inspection or when driving in road traffic.
To maintain the luminosity as much as possible, you should occasionally clean your headlamps really thoroughly.