I wonder if you could use the ducts on the Pilot's side panels for cooling....
It's the combo of the rear fender and the side panel that make the duct looking area - pretty much cosmetic, but after thinking about it, they may not be completely un-functional for your idea.
I wonder if you were to trim/bend/form the back end of the panel so it started pointing more or less towards the front of the cylinder (and this would creat a low pressure surface that would help force the air to follow the panel. (like tunnels under a race car)) and then come off the inside of the fender and form the scoop so it ducted the air to the sides of the cylinder.
Try using some styrofoam and make a mold that fits into the rear fender. That would allow you to cut out the duct and make a form for a fiberglass or Aussie Duner style vaccuum table (you paying attention Tony?).
That 1" thick blue stuff you buy at the hardware store works good. Since it's thin, you can just lay up layers inside the fender so you get a good fit for the mold. Stick the stuff together with spray adhesive.
It cuts great with any sort of sharp knife. You can also form it with rough sand paper and a right angle 1/4" air grinder with a sanding pad works great for blending, contouring and smoothing.
Just thinking out loud....