I hesatate to stay with this after the coments about the 'over the top w/c vw's, and Japanise go fast turbos, but thay ( the 'imports' from japan)are about the same size and weight as our speedys. As ther is no tech mags for us that I know of I take what I can get. So,. as for looks, it seems 'thay' use there wing tail things mostly for looks, as I will explain. Aerodynamics are verry importent lift downforce and drag. Drag Coefficient (Cd) = D/(1/2pVsquredA) D drag p air dinsity V velocity A car frontal aria. The slickest procuction modle out there is!!! YES an '02 NSXPorsche 911, and the venerable?? corvett. Cd's .30 -.29 VW Bug .49 :-(. Messin' with the drag on the speedy would to much , after all it's pretty slick in it present state thanks to Ferdie P., and those Italion boyzz at Giha body works. Ahhh but the lift and downforce are another matter. The rest I'm going to try and keep simple. Slice a speedy, or a supra, or a celica, or or, and you get the profile of an airplain wing. Bernoullis principle states that the faster a fluid moves the less pressure it inparts on it'seroundings. Tharefore the air in this case passing over the top of the car is faster then the air passing underneath. so you get lift. Not good {Now the wingthing, in short these things are for veeerrry fast cars, so say there manufactures. A canded coment from one stated that at 'street speeds thay apply so much down force as to slow you down (stack a pile of bricks on your ventige lugage rack, and you will feel it). He said these were designed for cars doing speeds of 180-300mph (top fuel drags). Hay can't say more about that} But we can increse down force a little bit by forceing the air passing under the car to move faster then the air going over,( not as hard as it seems, we allready have a gaping hole in the middle of our top side)(were we sit). 1. Lower the body 2. use a damn to direct the air around obstructions. This for all intent 'sucks you to the tarmak. Reverse Bernoulli. Enough!! right??