I'm looking to retro fit a tow bar to my 2008.

I've secured an original wiring socket from ebay, it has one grey plug at the end, I assume it plugs into a socket hidden under the bumper. However I have also seen another wiring loom with 3 plugs ( no tow socket). Am I likely to find that I am missing a part of a loom when I take the bumper off does anyone know and will have to purchase this second item too?

A grey socket or one plug sounds like caravan stuff.

The road lighting one has 2 plugs I think.

And yes there is an interconnect loom between the outside and inside of the car. 3 plugs

On the positive note. You can diy fit a socket easily with universal items. See top of maintenance and mods forum

This gives you an idea how they fit together.

https://rover.ebay.com/rover/0/0/0?mpre=ht...3700869195

I know it’s 13 pin and for caravan. But you get the idea.