I wonder if the primary control code should be open source. That's without respect to right to modify or reuse the code, just whether it should be mandatory that it be published. And it'd exclude things like user space apps and UI/UX stuff. But any of the code that controls or affects steering, acceleration, ignition, braking, and lighting, really seems like it's not OK to just consider it a black box, subject to DMCA, copyright, and trade secrets laws and thus risky (or flat out illegal) to reverse engineer and understand how it works. And right now a significant part of an automobile is a black box, and you do not fully own it.
It was supposed to be that patenting required you to fully disclose all the details of an invention. The idea was to not only make clear what you had a monopoly for, but so that others could learn from your invention and make something different that was better.