LOS ANGELES (Reuters) -For a businessman who perpetually struggles with broken promises, Elon Musk gave himself quite a to-do list Thursday night at Tesla's long-awaited Hollywood unveiling of its driverless robotaxis. After traversing the fake streets of the Warner Bros movie studio set in a sleek, silver two-door "Cybercab" prototype, Musk promised that the company's popular Model 3 and Model Y vehicles would be able to operate without driver supervision in California and Texas by next year. Musk said the company would start building the fully autonomous Cybercab by 2026 at a price of less than $30,000, and showed off a robovan capable of transporting 20 people around town - which he said would reshape cities by "turning parking lots into parks."