[NeilBlanchard]

The VW XL1 is the lowest CdA car ever produced. 1.5 sq m = 16.1 sq ft X 0.19 = 3.059 sq ft CdA.

Cd is more important than frontal area, because once the Cd get lower, it has a much larger effect on lowering the drag. It is much more practical and is actually easier to lower the Cd than it is to lower the area.

An example: take a medium sized car that has a frontal area of 25 sq ft and a Cd of 0.34. The CdA is 8.5 sq ft.

If you reduce the Cd to 0.2, then the CdA is 5 sq ft. If you tried to reduce the area to get that low, without also improving the Cd, the frontal area would have to be 14.7 sq ft - which too tiny to be very practical.