I have reduced my frontal area by 28 square inches! Thats gotta be worth a few MPG's!
You reduced by 28 square inches? How do you figure this? Just by lowering the car? No way, Jose'! Seems to me you didn't change the frontal area...just lowered the total a bit! Did I miss something? Air still goes under the car...at about the same mass flow rate (velocity / compaction).
An air dam would force a portion of this air up & over...not letting the mass get "tangled up" under the cluttered undercarriage. Of course, a smooth bellypan would be best ; that's been done, too! With marginal benefits.... -TH
Get a laser level and slap it against the side walls of each tire and see where the laser beam converges - I think about 300-500 feet is about as much toe in as you would want - 1000 feet intersection is about 1 degree - if the beam diverges from each side you have toe out - which is really bad as I found out!