Tata Motors said it will launch its ultra-cheap Nano car in Mumbai on Monday — a vehicle meant to herald a revolution by making it possible for the world's poor to purchase their first car. But few predict the snub-nosed Nano will be able to turn around the company, which has been beset by flagging sales and high debt, anytime soon. The Nano, which is priced starting at about 100,000 rupees ($2,050), is a stripped-down car for stripped-down times: It is 10.2 feet (3.1 meters) long, has one windshield wiper, a 623cc rear engine, and a diminutive trunk, according to...