> Copyright has zero application here unless you redistribute Tesla's code or binaries. Reverse-engineering is a legal practice (in US law, at least).

Reverse engineering to utilize software you didn't pay for and don't have a license or some other legal authority to use is unlikely to pass muster legally, versus for interoperability purposes.

https://www.eff.org/issues/coders/reverse-engineering-faq (Control-F "What Exceptions Does DMCA Section 1201 Have To Allow Reverse Engineering?")

Tesla can't sue you if you splice a switch into the seat heater relays! I don't know if that's a good idea. Or maybe they thought of that and they don't turn on unless there's some of key exchange.

That's BMW, not Tesla. Tesla only offers subscriptions for premium mobile network connectivity and FSD.

https://www.theverge.com/2022/7/12/23204950/bmw-subscription...

The cheapest Tesla's offered a one time unlock for rear seat seat heaters. Not any different from bmw, except bmw also offered a subscription option (bmw also offered a lifetime unlock... at a much higher price).

Using software without the license to is copyright infringement, full stop.

In what way? No copy was ever made.

Using a copyrighted work without license is copyright infringement. Not sure how to make that clearer to you.

> Using a copyrighted work without license is copyright infringement

Only for the kinds of “use” that involve the exclusive rights of the copyright owner (“use” generally does not), and even then not always, because there are exceptions to copyright.

If I put a book a don't have a license to under a table leg to make it stop wobbling, it is not copyright infringement