According to Gordon Murray—the ex-McLaren's Formula 1 designer responsible for the T.27 car—one day we all will be driving one of this vehicles. And wearing clown costumes. I don't care it's the most efficient car. It won't work.
The T.27 is designed to be driven in the city. Since it's ultra-light, Murray says it will be the most efficient car in its class, which probably sits somewhere between golf carts and failed European mini-cars from the 60s. The most innovative aspect is that it's made using a process called iStream: Instead of stamping metal sheets like in normal car factories, this manufacturing method welds metal sheets together.
That results in factories that are one-fifth the size of traditional ones, less energy consumption, and a car that looks like crap. And that, my friends, it's the problem with the T.27: If something looks like crap, people won't buy it, no matter how green and efficient it is.
Update: And yes, it looks like crap even with the fiber covers. People want real cars that feel solid. Not glorified golf carts painted in bright colors. [Daily Mail]