anyone know what this plug is for ?

[madmanmart]

whilst on the topic of lights. how would u go about fitting fogs to mk3 cl?

Change the switch and the headlight loom (one from the slam panel forward) with GTI spec items.

Its really easy.......

[Domo]

it an expensive process?

[thai-wronghorse]

Looms usually sell for around £15-£20 on eBay, expect to pay at least that again for a decent set of fog lights. You'll also need to the front fog headlight switch as well so you're probably looking at about £50 for all the bits you require to get them up and running.

[madmanmart]

^^ sounds about right