Electric vehicle maker Tesla is poised to expand its controversial FSD Beta program with a long-awaited download button that would allow customers to get new, unfinished versions of the company’s driver assistance software to test on public roads even though that software hasn’t been debugged yet.

Tesla CEO Elon Musk, who called a previous version of FSD Beta software “not great,” cautioned Friday evening that FSD Beta now seems so good it can give drivers a false sense of security that they don’t need to pay attention to driving while FSD Beta is engaged, even though they do have to remain attentive and at the wheel.

CNBC reached out to Tesla CEO Musk but they didn’t respond immediately.

Tesla sells its driver aid systems as a Standard Package called Autopilot and a Premium Package called FSD. FSD stands for Full Self-Driving In the U.S. According to Tesla’s website and users manuals, neither of these systems makes Tesla’s cars self-driving.

Musk promised his followers an FSD Beta button at the end of six months. Musk wrote on March 9th, 2021: “Build 8.3 FSD should have been QA tested by the end of next week. That’s about when the download button should appear.”

He also announced Thursday that Tesla will ask owners of the Beta button to first prove their driving skills before they receive access to FSD Beta.

Musk stated that the beta button would request authorization to use Tesla’s insurance calculator to evaluate driving habits. Beta access is granted to drivers who have been driving for seven days. The company started selling insurance in California’s home state in August 2019.

Hiromichi Minoshi, a Tesla board member and shareholder, shared Musk’s announcement. She wrote Friday that the company was promoting its approach by writing: “You have to be a great driver not drive. Which may become a new standard.”

Musk replied to Mizuno Friday night:

“Ironically, yes at this time. It can sometimes seem like the FSD beta system is so simple that you don’t need to pay attention, but it really is. Any beta user not being very careful may be kicked. 2000 beta users have been using FSD beta for nearly a year without any accidents. This must continue.

Musk’s tweet contradicts the facts concerning FSD Beta that were contained in the March 2021 California Department of Motor Vehicles Autonomous Vehicles Branch me.

Miguel Acosta from the DMV, Autonomous Vehicles Branch chief, was responsible for writing this memo. He spoke to Tesla employees that day, including Eric Williams, associate general counsel, and CJ Moore, Autopilot software director.

Acosta wrote that they informed him the FSD Beta program as of March 9, 2021, included 753 Tesla employees and 71 non-employees — less than half of the 2,000 FSD Beta users Musk alluded to in his tweet on Friday.

CNBC obtained directly the memo, as well as other correspondence, between Tesla and California DMV. These documents were previously published by Plainsite (a legal transparency site).

Tesla described their FSD Beta 2 features, even though they were not fully driverless technology, in their correspondence.