..but not rideshare on autopilot.

It's not unprecedented to have severe restrictions on software in EU. E.g. you can't use le Windows you legally obtained in France on two PCs simultaneously. Some vendors charge per-CPU/core licenses, some network software (e.g. certain PABX) charge even by the number of connected endpoints.

That is probably because in order to install Windows on even one PC (let alone two), you have to make a copy of it. Even if an installation is (somehow) not counted as copying, two identical installations is clearly implying a copy has been made somehow. And copyright means you don’t have permission to copy the software. Therefore, you have to have permission to copy it. Another word for permission is “license”, and the license explicitly says under which conditions you are allowed to copy it.

A car, on the other hand, is not copied after purchase, so a copyright license is not relevant. A “license” (as stated above) is not a general list of conditions you have to agree on; it is simply a list of permissions for you to do what copyright law (and trademark law, etc.) would otherwise not allow you to do. No such law restricts what a buyer is allowed to do with a car after a purchase is made, unless a contract is signed. A contract can state arbitrary restrictions, but for something to be a contract, it has to fulfill a number of conditions: it must be knowingly and willingly entered into by both parties, it must not be unilateral or even, in some jurisdictions, too beneficial to only one party. Clearly your standard so-called “license agreement” does not qualify. Ideally, and usually, a contract is something on paper which both parties sign. Do you sign such a thing when “buying” a Tesla? If so, does this contract allow resale? Does the contract require the reseller to require the second-hand buyer to also sign it?

There is however a business trick to go around this "limitation" of copyright, and that is by using a "server" which the car will call home to (like once a week/month/year), or simply accessing data from on a regular basis. By restricting "access to the server", Tesla can impose any limit they want including restriction on the after market. Owners would also not be allowed to fix their own car to skip the check or talk to a third-party server as that would go against the DMCA anti-circumvention (which is part of US copyright law).