Hi Peter,
MAX BMW:
Section 61-Electrical System, Parts 6 and 8.
61 13 1 352 577 - Cable Socket Female, 90 degree
61 13 8 061 761 - Cap for Flat Plug, 90 degree
I'm not 100% sure on the original setup, but I do believe this was how it worked for the R90S models. Others, who know the model and year differences better than I will jump in and correct me if I'm wrong.
Scott
Scott Blaylock