Tesla can't defy rules of mass auto production

The relationship between Wall Street and the auto industry has always been contentious, with automakers balancing their huge capital needs and long-term business model against investors' relentless focus on short-term returns. Tesla has turned this struggle on its head in its short time as a public company, grabbing market valuations at multiples of earnings that resemble Silicon Valley software startups more than any car company. Now, as the electric automaker struggles to move beyond low-volum