I looked around a little bit and found some potential options backing plates to get air onto/into the rotors (obviously the rest of the intake needs to be in place, I think this has already been tackled in other discussions). I'm offering these up as some options, but I'm quite fine with being told "what the hell were you thinking, that will never work."
Genesis Technologies Carbon Fiber Spindle Brake Ducts (
other goodies on the same site)
Some
Corvette kits - I'm not sure how much modification will be needed, but they aren't all that expensive. They also have kits for other vehicles, it's possible that they'd make a custom kit for the E9X.
Here's a
discussion on some relatively affordable Porsche backing plates, and a separate
link for retrofitting the parts to a NSX.
Do any of these seem to be reasonable options?