I think you are right; looking at the MB CD again it seems that it only has ASD. There is a hydraulic connection over the top of the diff and one connection and bleeder on the side.

To clarify, I m not trying to add ASR/ASD to my car just to put a new diff in. The sound of the old one is terrible :-(

I am only curious if I can plug the hydraulic connection and use it without the ASD/ASR function.