The Next Green Car? 50mpg is a good start

The Tata Nano's price and specifications are impressive: this car costs new what many used cars exceed: INR 100,000 or USD 1,953 or ZAR 18,850. My used Nissan cost more than that! And my car doesn't get 50 mpg or weigh only 580kg.
So why the fuss about congestion and more pollution? If every passenger car on the road in Europe, America and South Africa were replaced with one of these the congestion and air pollution would decrease, and fuel consumption go down, not up. Gas guzzlers like mine need to be replaced by vehicles like this, and the money saved by not having to pay 10 times or more for a vehicle could be used to grow the economy.
Now all we need is an electric version, and the world would be a better place. Companies like GM who can't innovate like this deserve to be put out of their misery.