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Some of the stock's rise may have come from short sellers covering their bets, but you don't get revenue increases like that without a decent product. The Model S does zero to 60 miles per hour in 4.2 seconds, has plenty of room (including a "frunk," a second trunk under the hood), and gets the energy usage equivalent of 95 miles per gallon. Last November it became the first electric to win the Motor Trend Car of the Year award; in May, Consumer Reports gave the Model S its highest car rating ever--99 out of 100. "It's what Marty McFly might have brought back in place of his DeLorean in Back to the Future," the magazine said.

After the battery-pack demonstration, Tesla's chief designer, Franz von Holzhausen, can barely contain himself as he talks about the design of the Model S. "It's like the leap of faith Apple (AAPL) took with the iPhone," he says, explaining why the car has a touchscreen instead of the usual physical buttons. "There's a cleanliness to the interior. The screen is the hero. We are in the midst of that transition toward a new way of thinking. For me, it's that iPhone moment."

That the company has come this far is no small achievement. But the next phase of Tesla's growth is going to be exponentially more challenging. Tesla's ambition isn't merely to win the title of hottest car in Silicon Valley, it's to simultaneously become the next Ford Motor (F) and ExxonMobil (XOM)--to be a profitable, mass-scale manufacturer and fuel distribution network. Not even Henry Ford tried to pull all that off.

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