Elon Musk says making autonomous cars is much harder than he expected, after Tesla's timeline for the latest 'full self-driving' software slipped again

• Elon Musk said he didn't expect making a self-driving Tesla to be so difficult.
• Musk said Tesla's latest full self-driving (FSD) software would arrive "soon," after the timeline slipped again.
• "Didn't expect it to be so hard, but the difficulty is obvious in retrospect," Musk tweeted on Saturday.

Tesla CEO Elon Musk said on Saturday that making a self-driving car was harder than he expected, after the company's timeline for its latest Full Self-Driving (FSD) software slipped again.

Self-driving was a "hard problem" that "requires solving a large part of real-world AI," Musk tweeted.

"Didn't expect it to be so hard, but the difficulty is obvious in retrospect," he said.

He also said that the latest version of Tesla's FSD beta software would be shipped soon. "I swear!" he added.

FSD, which doesn't make a Tesla car fully autonomous, currently costs a one-off $10,000, and was released in beta to some Tesla owners in October. It has all the features of Tesla's Autopilot - which brakes, accelerates, and steers automatically - plus it allows cars to change lanes, park themselves, and recognize stop signs and traffic lights.

In July 2018, Musk said that Version 9 of FSD would be released in August of that year. He then said in 2019 that there would be "over a million cars with full self-driving" within a year, per The Verge.

The billionaire's latest timeline update for the FSD Version 9 release came in April, when he tweeted that he'd be surprised if the software arrived later than June.