Ride-sharing, car clubs and other alternatives to ownership are already growing fast. Young city-dwellers are turning their backs on owning a costly asset that sits largely unused and loses value the moment it is first driven. Carmakers insist that such consumers are merely deferring buying a vehicle, pointing to the fact that people continue to drive at an older age than they used to. But the pronouncements of motor-industry bosses suggest that doubts are creeping in. At CES Mark Fields, Ford’s CEO, said that it would in future be “both a product and mobility company”.