Why Older German Cars Get BlamedVolkswagen may be the brand most closely associated with the crayon smell. In one r/cars Reddit thread asking why certain Mercedes-Benz vehicles smell like crayons, owners reported encountering the same aroma in Volkswagens, BMWs, Saabs, Volvos, and Porsches. The most common ingredients are old interior materials and heat. Then the first hot day arrives, and the interior suddenly smells like a box of crayons left on a radiator. But few automotive aromas are as specific, or as instantly recognizable, as the smell of crayons.