Christian Alvart changed the name of the (real) Subwaystation where U-Bahn-Lemmele resides from "Mohrenstrasse" to "Möhrenstrasse". The former is an old, somewhat racist term for a black person, the latter a word for a carrot.
The scenes where the characters walk down the stairs of the subway station were filmed in Berlin, the German capital. However, the scenes inside the subway station were filmed in the central station of Bonn, the former German capital.