Exotic car gear does sell CF inserts that fit flush just like the originals, albeit a little different slat style than the ones you are showing: https://www.exoticcargear.com/produc...-grills-vents/
Update to this thread, I went ahead and bought a pair of 997 turbo style vents on eBay. The key difference here was that they don't protrude outwards, for a slightly more sleeper look. I finished the fiberglass off with sem trim black paint, resulting in the look below.
In the upcoming weeks I'm looking to install some Cayman-R side decals to balance out the black as well. After some cutting of the inner vent, I was able to keep the intake snorkel installed as well.
Hope it's a useful reference point for yet one more Cayman mod!
search for "Porsche 987 Boxster / Cayman to 997 Turbo Side Vents" on eBay.
Warning though, their price isn't that far off from the other similar units
You're going to have to really want them, to justify it.
Imo the best scoops, by far, for any 987 is the Boxster Spyder scoops.