[ttoyoda]

For the cooling problem, and to avoid the work of making a belly pan, the red under the nose is the air dam (spoiler)(made out of a racecar tire) I was suggeting, if you leave the underside of the nose open.
Bring it closer to the tires and wheel well than i have drawn.

The red side skirts would tend to keep a lower pressure under the car, (if you have the air dam) which might be useful because all of these half-teardrop designs not only LOOK like the cross-section of a wing, they can actually produce significant lift. If the steering becomes unresponsive at high speeds (car wants to go straight even when you turn the wheel), you are probably getting front wheel lift. If the back end of the car wants to swing out and pass you when you go around turns at high speeds, you are getting more rear wheel lift than front. In any case, takeoff is undesireable.

The cyan is just a wheel well cover. The green under the back helps extend that lower pressure area under the car some more.. I don't have an opinion of the effect on drag one way or another.