[humdizzle]

i'll add my 2 cents.

most aftermarket aero is bunk. These companies dont have wind tunnels to test the product. Just because something 'looks' like its aerodynamic doesn't mean that it is. if you want what works look at what race teams are running.

[ame="http://en.wikipedia.org/wiki/Automobile_drag_coefficient"]Automobile drag coefficient - Wikipedia, the free encyclopedia[/ame]



Case in point:

The GTR has a better drag coefficent than a porsche 911.. despite looking like a giant transformer. It also generates 176 pounds of downforce at both front and rear axle 186mph. By comparison a 997 carrera generates 60 pounds of rear downforce at 180 and actually LIFTS on the front axle. the ferrari 458 makes similar numbers to the porsche. front end lift and very little rear downforce... google 'sport auto' tests if you dont believe it.

Its very very difficult to have both a low drag coefficient AND generate downforce. By adding spoilers, wider wheels, cooling systems you increase the drag alot. You'll see most sports cars on that list are > 0.30 while most economy cars (especially hybrids) are nearing 0.20 cD.

But most of all you have to remember that in order to achieve any reasonable downforce you have to be going in excess of 100-120mph AND turning to feel any added grip.