>You can't charge a subscription for something someone already physically owns.

I suspect the contract is worded so that the buyer of "the car" actually does not own the seats, or perhaps the heaters in the seats. If that's the case, do you feel that such a contract clause should be illegal? If so, you're claiming that there are circumstances in which it should be illegal to "separate out" some things that are usually "bundled together" (here, car seat heaters and the rest of the car) -- what general rule would you propose to decide what things are unacceptable to separate out like this? (In case you're thinking of proposing "things that are physically connected can't be sold separately", you will run into problems: Lots of raw materials, e.g., steel, need to be cut up to be sold in the quantities customers need.)

But let's suppose the contract does not in fact leave ownership of any physical part of the car with the seller. If you buy a router from an ISP, are they not entitled to also charge you a monthly subscription to use it to access the internet?