Almost immediately after Tesla unleashed its steering wheel- and pedal-free Cybercabs on the streets of Austin, Texas this month, regulators at the National Highway Traffic Safety Administration cried foul.

The regulator opened an investigation — an audit query, specifically — mere hours after the launch, aiming to find out whether the new Cybercab “meets all applicable Federal Motor Vehicle Safety Standards,” or FMVSS.

Days later, the agency followed up with a “Special Order” requiring the Elon Musk-led company to prove under oath that its Cybercabs meet federal safety standards, which were originally intended for human drivers, as Electrek reports. It’s a considerable escalation over its original query, and failure to do so by September 30 could force Tesla to pay a fine of up to $139 million. Falsifying information could land a responsible officer at the company in prison for up to 15 years.

Tesla’s efforts to brute force its self-driving vehicles onto public streets could end up meeting many more regulatory roadblocks from here, effectively making them illegal to sell. (Whether anybody will actually want to take on all those risks by investing in a fleet operated by Tesla is a separate, albeit just as hard to answer, question.)

Tesla self-certified its autonomous robotaxi as compliant with all vehicle safety standards, which assume a human driver behind the wheel. But given the lack of any physical driver controls, the NHTSA unsurprisingly has its doubts about them actually meeting these standards, given the Special Order.

The Cybercab’s lack of a brake pedal could especially make it difficult to meet certification standards. The FMVSS makes it clear that the brakes need to be activated “by means of a foot control.”

Put simply, Tesla appears to have taken some liberties in self-certifying its Cybercab, a decision that could end up coming back to haunt it. One possibility is that the EV maker temporarily bolted on physical controls, including a steering wheel and pedals, while going through the process, only to remove them ahead of delivery, as Electrek points out, a move that flaunts the FMVSS certification rules.

Amazon’s Zoox, in contrast, played by the rules and proved its cars were safe. The company managed to get an exemption from the NHTSA for its autonomous vehicles in July, which also lack a steering wheel and pedals.

It’s only the latest instance of an Elon Musk-led firm flaunting regulations to get what it wants, an ask-for-forgiveness-later approach that clearly isn’t going all too smoothly even under a government run by the billionaire’s allies.

Musk has made it clear again and again that he doesn’t believe in government intervention, with his business empire shamelessly breaking environmental rules, and abusing his workers.

“Regulations, basically, should be default gone,” Musk said last year shortly after forming the much-maligned “Department of Government Efficiency.” “Not default there, default gone.”

More on the Cybercab: There’s a Huge Economic Problem With Tesla’s Cybercabs