It's a decal. Ebay
Porsche Boxster 986 S 3rd Brake Light Decal Overlay 97 98 99 00 01 02 03 04 | eBay
Was kinda funny - the seller asked for pics of his decals installed on cars so I sent him mine, and he used it on his auction. He might have asked first, but I didn't mind. I was just surprised to find a pic of my car on some guy's ebay auction.