> If I buy a used vehicle for example, I have exactly zero relationship with the manufacturer. I never agree to anything at all with them. I turn the car on and it goes. They do not have any authorization to touch anything.
Generally speaking and most of the time, yes; however, there are a few caveats. The following uses common law – to narrow the scope of the discussion down.
As a matter of property, the second-hand purchaser owns the chattel. The manufacturer has no general residual right(s) to «touch» the car merely because it made it. Common law sets a high bar against unauthorised interference.
The manufacturer still owes duties to foreseeable users – a law-imposed duty relationship in tort (and often statute) concerning safety, defects, warnings, and misrepresentations. This is a unidirectional relationship – from the manufacturer to the car owner and covers product safety, recalls, negligence (on the manufacturer's behalf) and alike – irrespective of whether it was a first- or second-hand purchase.
One caveat is that if the purchased second-hand car has the residual warranty period left, and the second-hand buyer desires that the warranty be transferred to them, a time-limited, owner-to-manufacturer relationship will exist. The buyer, of course, has no obligation to accept the warranty transfer, and they may choose to forgo the remaining warranty.
The second caveat is that manufacturers have tried (successfully or not – depends on the jurisdiction) to assert that the buyer (first- or second-hand) owns the hardware (the rust bucket), and users (the owners) receive a licence to use the software – and not infrequently with strings attached (conditions, restrictions, updates and account terms).
Under common law, however, even if a software licence exists, the manufacturer does not automatically get a free-standing right to remotely alter the vehicle whenever they wish. Any such right has to come from a valid contractual arrangement, a statutory power, or the consent, privity still works and requires a consent – all of which weakens the manufacturer's legal standing.
Lastly, depending on the jurisdication, the manufacturer can even be sued for installing an OTA update on the basis of the car being a computer on wheels, and the OTA update being an event of unauthorised access to the computer and its data, which is oftenimes a criminal offence. This hinges on the fact that the second-hand buyer has not entered into a consentual relationship with the manufacturer after the purchase.
A bit of a lengthy write-up but legal stuff is always a fuster cluck and a rabit hole of nitpicking and nuances.
