I haven't done any testing with this alone as far as my FE, but I'm thinking of re-doing it after reading about basjoos's car and the DreamPrius concept. With this AND my wheel skirts, I picked up 2 mpg highway, to 47 mpg.
The middle picture with the air intake openings outlines my original opening and my modified one after the car was overheating.
The car's still getting hot on the highway. I think the cooling issues are probably due to the amount of air I'm pushing below the car, and resulting eddy currents limiting flow through the radiator. Andrew, the guy with the white civic, has a similar car and engine with a much smaller air intake door and he's doing fine with cooling.
After more reading, I think it should be more advantageous to go with a design like:
Ideas/help/comments on my mad MS Paint skills?
