Vehicle Specific Towbar Wiring Kit

[victor meldrew]

I've transferred the towbar from my old mk 1 to a mk2 and bought a wiring kit from vw for £53

It's for a 13 pin socket

The main cable has only four wires in it and the instructions are not really clear

Has anyone used one of these that could explain how to fit it?

I can't even find the plug it connects to.

I need to do it by Friday afternoon or suffer the wrath of the wife when I tell her were staying home this weekend