Hybrid
I did look at the spoilers and i think that the evo would be extremely difficult to graft but who am i to say i believe in the theory you can do anything if you put your mind to it.
So imagine the spoiler on the car (completely finished) now lets say you have not removed any of the bugs bodywork under the hood IE... the spare tire area. now put the oil cooler as far forward as you can inside the spoiler depending on how much room you have left between the cooler and the most forward part of the bug you could build a box to enclose the cooler and at the back end of this box you could use a NACA duct to force the air out onto the brakes now the NACA duct may face rearward of the actual brake but using a hose to route the air to whever you want it is the idea. Does this help if not ill E-mail you my PH number and you can ask me