Cars withe EULA
"(There's already a black market for pirate tractor software that allows farmers to circumvent John Deere's proprietary systems.)"
That's an inaccurate description of what's going on. The "proprietary" systems are designed to prevent farmers from making their own repairs, or from going to a non-Deere-authorized repair center. And those rules are starting to be overridden by state "Right to Repair" laws. These will affect virtually ALL high-tech companies that try to limit competition in the repair business.
The question is, if I buy a car - or a cell phone, or a computer, or any other tech - do I OWN what I paid for, or do I merely have a non-transferable license to USE my car in accordance with the car's EULA?
Biting the hand that feeds IT
