George Hotz, legendary hacker and Silicon Valley iconoclast, planned to start selling a $999 autonomous driving upgrade kit by the end of the year. The kit, he said, would transform a regular car into a sophisticated driver assist package on par with Tesla’s Autopilot.

He dropped those plans in a huff after safety regulators told him to answer some questions before he could start selling the kit.

“Would much rather spend my life building amazing tech than dealing with regulators and lawyers,” Hotz posted on Twitter. “It isn’t worth it.”

Hotz planned to start with a kit that would fit with an Acura ILX, and move on to other cars. On top of the $999 for the kit, his company, Comma.ai, would charge $24 a month for software updates.

That’s far cheaper than new cars being sold with driver-assist technologies such as automatic braking and lane-keeping, many of which go for $50,000 and more. A fully equipped Tesla Model S goes for well over $100,000.

But Hotz was put off by a letter he received dated Thursday from the chief counsel of the National Highway Traffic and Safety Administration. The letter demanded “full compliance with your legal responsibilities” and directed Hotz to answer a series of questions about the product and how it worked.

Dealing with regulators and lawyers was too much for Hotz.

Hotz became famous as a hacker at age 17 when he wrote “jailbreak” programs for the iPhone so they’d work on cheaper networks. He is also known for hacks and attempted hacks into other smartphones and the Sony PlayStation. Sony sued Hotz and reached an out-of-court settlement.