What cars that are driven within designated environmental zones must display a particulate matter sticker?

All cars driven within designated environmental zones in Germany must display a particulate matter (Feinstaub) sticker, regardless of whether they have petrol engines, diesel engines, or electric motors. These stickers serve to prove that the vehicle meets the required emissions standards for entering these zones. Even electric vehicles are required to have the sticker, even though they do not emit particulate matter, to ensure easy visual compliance checks by authorities. This rule applies uniformly to all vehicle types to maintain clarity and enforce the environmental regulations within these designated areas.