Just thinking out loud, but wouldn't it be more beneficial to run the ducts to the brake calipers, since this is where fade originates? Since the rotors are spinning and can basically cool themselves down better than stationnary, immobile calipers, getting air to the calipers might be better...
BTW, I'm thinking of doing the same since I got new fogs for the 'Stique, but couldn't use the stock spots for them. Might try running a duct from the driver's side to the airbox (which have holes in the bottom of it - great high RPM pull

).