Planning to work on mine soon. I don't remember looking at our dust shields before (should have looked when I had the rotors off for the extended wheel bolts), but I would imagine we have them, and they block air intake to the center of the rotor to some degree. So I was planning to cut into the dust shields and mount a flange there, like Modshack's Audi pictures here:
http://www.the370z.com/diy-section-d...tml#post101626.
I'm thinking I'll probably have a friend with some metal working equipment (proper cutters, a plasma cutter if necc) help with cutting the right-sized hole in the dust shield, and then just rivet a flange into there, aiming for as close to the center as possible (at least, far enough in that the air is mostly being drawn through the center of the rotor rather than dumping on the back surface of it). I'll try to get some pics when we get to this.