The symbiotic relationship between cinema and fashion is well known. It's clear: they need each other in their particular creative processes. Films use costume design to enlighten certain characteristics or to capture the course of time, for instance. Whereas fashion, uses cinema as one of its main sources of inspiration.
But it is also true, that there are certain movies, in which costume design plays a principal role. And that is the case of Fassbinder films. He knew how important clothing is to reflect personality -he was often seen with a leather jacket and dark glasses- hence he relied the costume design of his films to the amazing Barbara Baum.
From The bitter tears of Petra Von Kant.
Here you can find an interesting article about Costume Design in German Cinema.
Forgive my lack of originality: Lili Marleen.