Jeremy Clarkson, best known as the former star of the BBC’s Top Gear, has declared self-driving cars as not ready for prime time.

The present host of Grand Tour, whose career took a detour after a physical row with a colleague sent him down another road, was “nearly killed,” according to the UK’s Sun, whilst driving in a self-driving car which made a couple of “huge mistakes.”

Clarkson’s warning to the public comes as the UK’s Chancellor Philip Hammond is pushing an agenda this week to see self-driving cars receive a green light on UK roads by 2021 with hopes of boosting a £28 billion ($37 billion) industry touting 27,000 jobs.

“I drove a car the other day which has a claim of autonomous capability and twice in the space of 50 miles on the M4 [roadway] it made a mistake, a huge mistake, which could have resulted in death,” wrote Clarkson in the UK’s in the Sunday Times magazine. “We have to be very careful legally, so I’m not going to say which one.”

Despite Hammond’s desire to go full speed ahead with self-driving cars, Clarkson decried the technology that is in his view yet “a very long way off,” adding: “For now, we’re miles away from it.”

“You drive one of your driverless cars over the Death Road in Bolivia and I’ll buy one, Clarkson said. “Sit there with your hands folded and let it drive you up there, then squeeze past a lorry with half the tire hanging over a 1,000-foot drop while the car drives itself. Fine, I’ll buy into it.”

Although Clarkson declined to say what famous brand manufacturer “nearly killed” him, the UK’s Sun noted that Audi is “among those who will start” offering advanced autonomous cars next year.