Check this out. Scroll about half way down. Just a simple plate to bolt up to. I say simple. But could cost more than you would want to pay being there would be some welding involved. Also scroll all the way to the bottum and check out the black end piece attachment that could be had.
Brake cooling ducts - anything new for 2010 - NAGTROC - The Nissan GT-R Owners Club
I'm really going to see what I can make for myself. Intake ducts for the front are dime a dozen from what I've seen. But the one to the rotor are something else. I feel it could be easily be done though. More or less a flat solid piece (but pretty) with a hole where a ring can be welded to to connect the piping. I'm going to check out are cars this weekend to see if the exsiting dust shield can be transformed somehow. Glad I have several friends who can tig.