How about STATTAUTO München Carsharing
? It's got a PLZ search with maps. You put in the PLZ which you get from the other links, and then the form tells you what part of town you're in, and then click on "Zur markierten Station" and you get a map of the Stattauto Station that's in that PLZ.
Still not sure exactly what you want, but a combination of these things will get you all the PLZs in Munich and maps of the area. Most paper maps have the PLZs marked on them too actually.