Take some time and lay under your 2. look for places that might be drag producing protrusions. Can they be improved by removing them or putting in a sheet of plastic, foam and glass cloth, etc. Look for places we can route air from beneath the car.
I.ve been considering the area just behind the front tires. Cut the fenders to allow the air to flow to the side of the car, and extend the side skirts foward to force the air upwards. Things like that. We can bump heads on it next time we get together.