Jay,
Ordered mine yesterday. I'm surprised these aren't generating more interest, especially given that the pros and cons of a mod like this were debated recently:
http://forums.pelicanparts.com/porsche-911-technical-forum/910200-vent-holes-grill-rear.html
I doubt that it has much effect on cooling or performance but I ordered one because it looks well made and should further differentiate my car from all the other red mid-year 911s out there.