Economist: THE cacophonous capillaries of India’s infrastructure may be about to get a lot more clogged. By the end of 2010 there could be as many as 300,000 Tata Nanos on India’s roads. Well before its launch, the tiny car had become an object of loathing for environmentalists (unfairly–it is one of the cleanest vehicles around). But for potential buyers, what matters is whether it is any good. Despite the Nano’s size (it is a bit over ten feet, or three metres long) its interior is …