A prototype of Audi's A1 e-tron was first presented last year at the Geneva Motor Show. But, before the electric car can go on sale, it must undergo a battery of rigorous tests and trials.In Munich, a fleet of 20 A1 e-trons has hit the streets to see how the little electric car does in everyday conditions. It's the kind of urban environment the A1 e-tron was designed for. But the car must also prove its mettle on tougher terrain. drive it! accompanied one on a rally in the mountains.