The cars are built using an efficient process that first attaches most of the car's parts to the chassis, and then adds a pre-painted body as a last step, similar to the way Formula One vehicles are built.
Look at the gallery below, and you'll see that the car is so tiny that three of them can fit into a single parallel parking space. If all cars were this size, we'd live in a utopian energy-saving world.
The T25 should be available in two years, with an all-electric version, the T27, following later. Link