A Tesla software hacker has found an ‘Elon Mode’ driving feature that seems to allow Tesla vehicles with Full Self-Driving to operate without any driver monitoring.

Tesla CEO Elon Musk might have his very own supersecret driver mode that enables hands-free driving in Tesla vehicles.

The hidden feature, aptly named “Elon Mode,” was discovered by a Tesla software hacker known online as @greentheonly. The anonymous hacker has dug deep into the vehicle code for years and uncovered things like how Tesla can lock you out of using your power seats or the center camera in the Model 3 before it was officially activated.

After finding and enabling Elon Mode, greentheonly ventured out to test the system and posted some rough footage of the endeavor. They did not share the literal “Elon Mode” setting on the screen but maintain that it’s real.

The hacker found that the car didn’t require any attention from them while using Tesla’s Full Self-Driving (FSD) software. FSD is Tesla’s vision-based advanced driver-assist system that’s in beta but is currently available to anyone who paid as much as $15,000 for the option. The software was the subject of an internally leaked report last month that indicated FSD has had thousands of customer complaints of sudden braking and abrupt acceleration.

Tesla’s Autopilot system, the automaker’s first-generation driver-assist system for highways, requires you to nudge the steering wheel to confirm you’re being attentive during use. Owners often complain about the frequency of the system’s checks, leading some to call it “nagging.” FSD users are also subject to the frequent nudging, and at times, it seems to require enough force that could inadvertently shut off the system.

In addition to the existing hands-on-steering confirmation, vehicles that have a center interior camera (above the rearview mirror) will observe drivers to make sure they’re looking forward — but that’s also pretty finicky. For instance, I’ve found that I’m unable to wear a baseball cap without the system constantly nagging me to “please pay attention to the road,” seemingly unable to tell that my eyes are looking forward. It even disabled at some point and said I would lose my FSD privileges if I did it four more times.

But for greentheonly’s near 600-mile test on Elon Mode, they found no such nagging. The test was conducted in what the hacker claims was a company-owned vehicle, based on their comment that they “could not get a non-Tesla car” to try in Elon Mode. In the video, it seems greentheonly is driving an early Model X, which notably, could be old enough to not have an interior camera at all. It’s not clear if this model has the camera or how greentheonly got access to the car.

Among the notes greentheonly provides in the Twitter thread, the hacker states that the system still seems to change lanes randomly and ends up driving slow on the highway. Whether this version of FSD will be available to regular owners is unknown. In December, Musk hinted that nag-free driving is coming.

Greentheonly adds that Tesla’s software is more secure than ever compared to 2017, when the hacker first started inspecting it. Despite their ability to consistently get around Tesla’s security, greentheonly tweets that the level of care Tesla puts in its software is rare to see compared to other cars they’ve touched, and it’s a “nice puzzle that keeps getting better.”