Fiberglass hood mods... crazy?
On newer cars the have a belly pan that causes the air to be channeled out from the underside. When a car is in motion air builds up in the bay and is swirling around, what this pan does is eliminate the air from the bottom so just the air from the grill is coming in. The pan has vents towards the back so that air is forced to flow over the engine then out the back. Thats how new cars can have a smaller grill, more efficient cooling, it also adds MPG. (less drag from swirling air, same idea as a tunno cover on a truck bed) High speed salt flat cars have very smooth bottoms, and airplanes are round for a reason. It's all about less drag. I don't know if something like this would work for you but it might be a viable alternative.