Thanks Guy's...

I have pulled the back pannel off tonight (in the boot, where the carpet covers all round the nav unit), and I saw where the nav aerial plugs into the loom, but what confused me is that there is a plug that runs along side the aerial cable (it's a small flat plug with 3 wires)

I was wondering if that has come unplugged from somewhere?? I had a quick look but couldn't find anything.. does anyone know what this is???