Toothpaste for dirty headlights, oven spray for greasy rims and coffee beans against foul smells in your car. These household tips are often used by clients to clean their car. But they are not always harmless. 

A lot of potential damage can be prevented by giving the right information at car wash companies. Most car wash operators request their clients to use only specific cleaning detergents. But it helps to tell car owners what is the reason for that request.

If the car owner is aware that some soaps can seriously contaminate the water purification system that is used in the car wash, they might refrain from using their own soap.

The problem of course mainly exists in self car wash bays, where clients can save a few bucks by bringing their own soap. They often find tips in Facebook groups where car owners meet or on other like-minded internet fora. Users give each other tips and publish lists of tolerant self car wash companies. Luckily most users of those forums react in a positive way when car wash owners and polish specialists show up and tell them otherwise.

Toothpaste

A tip that keeps reappearing is to clean your front headlights with toothpaste. “Bad idea”, says Dieter Thiel, who is an expert in vehicle preparation and import of foreign cars. “Sure, to some extent it works because of the polishing element in toothpaste.” But he doesn’t recommend using it. “Simply because it’s illegal. Headlights have an official type approval. Any alteration to the headlights could result in the type approval being invalidated at the next inspection.”

A household tip for clean rims has a similar negative effect: oven spray. The substances contained therein can corrode the surface and thus lead to damaging the rims.

On using household detergent for cleaning your cars, experts judge more mildly. No damage is to be expected when cleaning the interior of a car, for example the dashboard. But dishwashing detergent should not come into contact with the sensitive surface of the paintwork, “because the surfactants in the detergent can corrode the paint,” warns Sören Heinze of the Auto Club Europa (ACE).

Clean air with coffee beans

Coffee against unpleasant odors is mostly safe. But in order to have a fresh smell in the car in the long run, the cause of the foul odor must also be eliminated.

Most experts strongly recommend using the cleaning agents which are specifically developed for cars by the car washing industry.