Tesla's "We, Robot" event left analysts with more questions than answers.Wall Street was broadly disappointed by the lack of detail, and skeptical of Elon Musk's timeframes.The EV maker's stock dropped as much as 10% in early trading on Friday.

Ever the showman, as well as one of the most successful entrepreneurs of our time, Musk used a Warner Bros movie lot to show off a prototype of what is now being called the Cybercab. This version was a sleek, silver, two-seater without the familiar steering wheel or pedals of a traditional car.