The thing which comes to mind (remembering a little of my aero classes) is that you want to reduce the front air access to the engine bay to the minimum required for cooling. The air going into the bay ends up under the car body, and if there is too much, it piles up in the bay and under the car, and creates drag, a lot of drag. I see some big holes there.
That's why race cars, and regular cars as well to a minor extent, have minimum holes in the front, and air dams under the chin of the front. Race cars also have real side skirts and bottom closure panels (and a few top end exotics as well) to be even more efficient at this. These designs are to reduce the total vehicle drag.
Nascar cars have air dams and skirts clear down to the pavement for maximum effect at the 200 mph speeds they can run at.
Basically, I'm saying that if you don't need the large open areas for cooling requirements, get rid of the excess. My impression, having owned 2 GTV6s, is that the original design was adequate.