You can buy the Euro switch on VWVotex (do a search) for about $40.
There is also instuctions on how to wire it up with just a piece of wire
and a bulb.
I believe that C. in your picture of the tailight is the one used for
the rear foglight.
David Michalski , D.V.M.
-='04 VW R32 & '01 GTI GLX
Have Chip Will Travel