Whilst changing my passenger side foglight today (what a knightmare and thats the easy one) I noticed that part of the loom which has the foglight plug also has a spare plug sitting there doing nothing.

 

The part number is 1jo 973 702 which just tells me its a plug.

 

I tried taking a pic (didnt turn out that well)

 

 

Any clue what it might be for?

Outside air temp sensor. Faces forwards and clips into either a piece of metal or plastic just off to the side of the crash bar. The bottom of it is the "clip" that holds it in place.

ah makes sence. The fact its not in its right place will explain why its so different to my caddy's readings too.

My old golf used to have one plugged into the inner wing. At least I know where this one is now.