b180 speed sensor in CVT needs replacing after only 65klms. I see that in the UK they also had problems at 37Kmiles and many of those have been repaired by Mercedes . Is or has there been a repair program or recall on this problem in Aust?

I have a 2008 Mercedes Benz B180 CDI. It is fine EXCEPT for the sunroof. I am totally frustrated. The sunroof malfunctioned although I did not use it very often. It is the fold back "Venetian Blind" style. Mercedes Benz service dept Adelaide told me they were a terrible installation and design. When it malfunctioned they just obfuscated and stood around wringing their hands. The best they could offer was too replace the unit at the "special" price of $5000AUD. I obviously rejected this kind offer and took it to another service place who discovered a small broken piece of plastic was causing the trouble. This small part is apparently unobtainable - which I find remarkable. The roof whistles when driving at about 100 k/hr and is intolerable. Has anyone suffered the same problem and could anyone tell me the actual manufacturer of this disastrous roof? I am also told it was also fitted to a Renault model. I am unsure of that.