German Polizei Corner

Avoid pollution, noise in neighborhood
During the cold season, some vehicle owners who do not possess their own garage like to idle their engines as a way to clear the windshield of ice and snow without having to scrape and warm up the interior of the vehicle. Doing so creates unnecessary pollution.
Idling engines creates noise pollution and releases toxic material into the environment. Additionally, idling is an unauthorized method of warming up vehicle engines, according to German road traffic rules. Disobeying this rule can result in a high fine. The only exceptions to this rule are cabs, which may have idled engines during cold weather.

A cold engine emits twice or even three times more toxic material due to the higher number of revolutions. It is also extremely loud.
Drivers who prefer a pre-heated vehicle should consider getting a low-emission auxiliary heater.