Tesla (TSLA) CEO Elon Musk tweeted on Tuesday that he tried to get a meeting in 2018 with Apple (AAPL) CEO Tim Cook about the possibility of Apple buying the electric vehicle giant — but that Cook refused.

Musk was responding to a tweet from ARK Invest director of research Brett Winton about Apple’s newly reignited vehicle ambitions when he let the news slip of what could have been a blockbuster deal.

“During the darkest days of the Model 3 program, I reached out to Tim Cook to discuss the possibility of Apple acquiring Tesla (for 1/10 of our current value). He refused to take the meeting,” Musk tweeted.

Tesla has a current market capitalization of $606.9 billion, and on Monday officially joined the S&P 500 after achieving four consecutive profitable quarters.

Apple declined to comment on Musk’s tweet.

Tesla has come a long way from ‘production hell’

The time frame Musk is referring to is what he previously called “production hell,” a period when Tesla was attempting to ramp up production of its Model 3 vehicle back in 2018. The car, which is now Tesla’s volume seller ahead of the Model S and Model X, was seen as integral to the automaker’s survival. At the time, however, the company was beset by production issues.

In 2019, Craig Irwin of Roth Capital Partners told CNBC during an interview that Apple had sought to acquire Tesla in 2013 for $240 a share. The deal, however, never came to fruition.

The past year has seen Tesla’s stock price skyrocket as retail investors piled into the company. It’s now up 592% for the year, making it one of the best performing stocks of 2020. At market close on Tuesday, it was trading at just over $640 a share.

Apple, meanwhile, is rumored to be working on its own autonomous vehicle. Reuters reports that the company could have the car, part of Apple’s Project Titan program, on the road by 2024.

Musk’s tweet on Tuesday comes from a mercurial CEO known for using the platform to make news. In 2018, he tweeted that he had secured funding to take Tesla private at $420 a share, prompting fraud charges from federal securities regulators that were eventually settled.

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