1981 928S mysterious plug connector - help needed

[Attylla]

Hi Pelicans

I'm working on my 1981 928S and came across this mysterious plug connector.
I have no clue what it should lead to as I got the car incomplete and partly disassembled.
It's located behind the passenger/right side rear quarter interior panel.
It routes from the main harness around the rear speaker area.
2-pin male connector with Black/Blue and Black/Green wires.

Does anyone know what this could be for?
THere is no such wire on the driver's side only the passenger.

Please help if You can