Tesla boss Elon Musk has unveiled the firm's long-awaited robotaxi, the Cybercab, at the Warner Bros Studios in Burbank, California.

The futuristic-looking vehicle, featuring two wing-like doors - and no pedals or steering wheel - deposited Mr Musk in front of an audience eager to hear details about a project he considers key to Tesla's next chapter.

At the event, billed "We, Robot," the multi-billionaire reiterated his view that fully self-driving vehicles will be safer than those operated by humans and could even earn owners money by being rented out for rides.

However, investors have not yet shared his enthusiasm—Tesla's share price fell after markets opened in the US on Friday morning.

The value of its stock was down more than eight percent, trading at around $219, at 11:45 Eastern Time (16:45 BST).

Meanwhile shares in ride-hailing rivals Uber and Lyft - which have their autonomous ambitions - were each trading up to 10% higher.

Questions are being asked about Mr Musk's prediction that production of the Cybercab would begin "before 2027," given his track record of failing to meet his own deadlines.

"I tend to be optimistic with time frames," he quipped during the event.

He said the Cybercab - which would compete with rivals including Alphabet-owned Waymo - would cost less than $30,000 (£23,000).

However, analysts have cast doubt on how realistic that plan is.

"It will be tough for Tesla to offer a new vehicle at that price within that timescale," said Paul Miller, from research Forrester.

"Without external subsidies, or Tesla making a loss on every vehicle, it doesn't seem plausible to launch at anything close to that price this decade.