Originally Posted by dchen
Commercial airlines are designed not for maximum speed. It is designed to minimize cost per seat, and maximize lift/drag ratio. Commercial airplanes also have alot of control surfaces to allow it to fly at different speed and for the maneuvers they perform. You have got the ailerons, elevator, rudder, trim-tabs, spoilers/airbrake, and flaps. If you notice lately, alot of airplanes now have huge winglets, especially the Boeing 737s.
Race car aerodynamics are very different than airplanes, because they have different aerodynamic purpose. Airplanes are designed to fly at an optimal speed and altitude, or dynamic pressure. Race cars are always in transient state, unless you are racing on ovals. Cars also don't need to worry about fuel mileage that much, so it can afford to carry the extra drag penalties from the small aero devices the cars are carrying. Even if you have a L/D of 0.5, it may still achieve the performance criteria of the race car engineers, because they may have a more powerful engine to overcome that extra drag.
One thing though, those Honda wings are some of the weirdest, yet funniest thing I have ever seen.