Yeah the side skirts in the picture I posted are OEM polyurethane. They are the same style as on the GT3 MK1
I opted for the Fiberglass GT3 MK2 style on the 2002-2004 GT3 and 996 911.
they are aftermarket from precisionporsche.com a very small shop.
The sideskirts attach using double sided tape and two factory clips.
prepainted factory parts are cool if you can get the skirts themselves at a cheap price. Otherwise you aren't saving money. I think anything under $1000 is good.
$700 seems to be the going rate on Ebay for unpainted OEM polyurethane.