Last weekend, Mike Levine, Ford’s head of product communication, accused Tesla of selling “vaporware” during a heated exchange over Twitter.

The comments came after Ross Gerber, a Tesla investor, wrote that Ford should stop comparing the Mach-E to the Model Y. In his clapback, Levine wrote that “Mach-E customers drive away with a car. Tesla customers drive off with vaporware.”

In a follow-up tweet, addressing dealer markups, Levine added that he wished Tesla customers “good luck reaching out to Tesla to get your FSD.”

https://twitter.com/mrlevine/status/1373646122548301833

Tesla’s so-called Full Self-Driving came under scrutiny recently when it emerged that the company’s own legal counsel said that the system did not, nor would it, despite its name, constitute “autonomous driving.”

Read Also: Tesla Says That Full Self-Driving Beta Is Not An Autonomous Drive System

Although the company carefully avoided claiming that FSD is a fully autonomous system in its communications, the feature’s name and its $10,000 price tag raised more than a few eyebrows.

The distinction between Full Self-Driving and fully autonomous is also subtle enough that some are worried consumers might be confused.

Although Tesla claims that it makes the feature’s limitation clear to customers, Tesla CEO Elon Musk wrote on Twitter recently that some of the beta test’s drivers had the feature removed from their vehicles because they were not paying attention to the road while driving. That’s an issue that has popped up many times with Autopilot and has even resulted in accidents.