I drive alone an overwhelming majority of the time; I like the idea of a single-seater. I'm planning on building one from mostly vintage car parts.
Lighter weight + smaller frontal area => better city and highway MPG. I think it'll be easier for me to lower the A value of Cd*A then the Cd value. Lowering the Cd is even better.
(14 sq ft)*(0.32) = 4.5 sq ft of drag area
The GM EV1 is 3.95 and the Honda Insight is 5.1 according to Wikipedia:
Automotive aerodynamics - Wikipedia, the free encyclopedia
If you sit in the center you can be further away from the door than with a regular width car, which should offer better side-impact protection. I plan to have more of a cage, and front and rear sheet-metal to offer decent crumple zones.