A while ago I was looking for the quad fog lights and only found OEM. Do you have a link for the Chinese ones? Thanks in advanceLight output of these original quad types are terrible. So if you need fog lights (I keep them on when ever there's dark, because I have night blindness), I'd put HID/LED bulbs inside those original ones, but if it's just for looks, then quads are nice. I woudn't pay extra for the original quads, but buy cheap Chinece ones, because there's a chance thay have better light output. As the light output is so weak, I decided to improme my HID headlights and ordered 55W upgrade for them. This way I have enough low beam output even with the crappy quads.
With quad conversion you need light units, covers, electric plugs to fit quad units and new smaller airducts to go round them. They are vertically adjustable.