You left with the hardware, and accepted that it was locked. You didn't pay for access to it.

In my edit which was well before your reply, I explicitly stated I'm okay with you bypassing a lock like that to gain access to heated seats. You have a right to modify your car and tough luck if tesla didn't protect it well enough. That's not your problem, that's theirs.

FSD is another matter though. It's actively developed software that's pushed to the car if you paid for it. Software that will in the future push liability onto Tesla if they are successful. Tesla doesn't have any obligation to provide that software, updates, or access to it regardless of any hack that's done, and I imagine the NHSTA would even require them to devise a way to prevent access due to liability issues that might arise.

Edit: one is accessing something you own but don't have access to through a hole they left open. The other is piracy/theft