I just thought there might be someone interested in this info i just got, it is the documentation for the interface you can get through parrot to use the multifunction steering wheel, I had one of these installed in my previous Merc C class and worked like a charm:
Parrot - PDF
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporscheparrotmk6000.pdf
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporscheparrot3200_3400.pdf
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporsche.pdf
Parrot - PDF
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporscheparrotmk6000.pdf
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporscheparrot3200_3400.pdf
http://www.parrot.com/documents/en/support/schemasdinstallation/pdf/pinoutporsche.pdf