Take a look by the window pillars
If your Euro model is like the U.S. spec vehicles the connection is under the rear window pillar, in some cases there is a connection on each side, on others it's a single connection. Look to see where the electric window strip widens slightly a little lower than where the seat belt harness attaches to the side frame. Your connection is under the molding at that point.
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan