madmods: the spoiler you've got a photo of is actually a factory Porsche Aerokit II wing. Per the kit, it is installed with a fiberglass trunklid, and the speed controlled spoiler is removed.
I've got one, and I added the Cayman style wing to the trunklid below the Aerokit wing:
FWIW, the racer in me digs the cup car wing on that Cayman. I would LOVE to see a Cayman prepped to run in the GT class of ALMS or Grand-Am!!