My tiny little car certainly seems to benefit from a 5 inch airdam. (Still 3 or 4 inches between it and the road. I think, like the Mighty Mira, it's reducing the drag/visible frontal area of the front wheels, which I assume may be greater in proportion to the size of a small car. But in the case of my VW Station wagon which sits lower to the ground, I could see no difference.
