You're contrived example is contrived and not at all a comparable thing, because a car first of all is not a thought it is physical property as opposed to this intellectual property. Property rights as in physical property rights have been a thing for as long as humans have formed into a society. This concept of intellectual property or the continued ownership of thoughts that you have released into the world have not been a concept since humans have formed societies. It is absolutely a legal fiction that has been created and it is a fairly modern development the idea that you can not only own a thought but continue to exert control over it post sale.

Intellectual property rights attempt to exert continued control of the creator post sale or post delivery of that intellectual property. Even to the point of controlling that in the terms of selling it again it's saying that if I purchase your creative work I don't own that I can't control it I can't do what I want with it. Now if we relate this to your car example car companies have tried this nonsense and you know what it has failed miserably for them. We don't even have to use the idea of an automobile as an example because again it's not really comparable this manufactured thing. Instead we have a very analogous example that has happened in modern times relating to the sale of intellectual property. This comes in the form of books. Authors and publishers of books attempted to exert control of what they believe is their intellectual property post sale. Even to the point of restricting the sale of that book to another person. Even to the point of saying people couldn't modify said book and then sell that item again. This was all thrown out as laughably ridiculous because it is. Yet your argument is somehow you want to exert control of your thing when it's been sold or resold or resold again. This is an absolutely constructed legal fiction and I'm very confident you have lost the reason why society allowed this legal fiction to be constructed.

Societies didn't come up with this concept of copyright and patents and ownership of intellectual property is a legal fiction because they thought it was a good idea for the creators to have some sort of orwellian control in the minds and thoughts and actions of people who chose to consume it. The reason for this is clearly stated when you study history it was so a creator could realize a profit from their work for a limited time to ensure that they would be encouraged to make more works. The key there is for a limited time it is not in perpetuity or effectively in perpetuity and it is not to continue to exercise control of it once it has been sold to another. It is the limited time function that we can say it must be sold but after a while this should return to the public good to enrich the public culture as a whole. Content creators seem to believe that they don't have to honor this deal because we've allowed it to be corrupted and twisted so that it is effectively an infinite thing where you can exercise infinite control over the actions of other people once you've sold it to them. They also seem to believe like you do that there is no bargain with society you have forgotten that it is a legal fiction to encourage you to create more but ultimately creative works are about enriching a society and a culture as a whole and so if those works never return to the culture and to the society at large there is no bargain anymore. Content creators have become Petty slumlord rent collectors who are simply regurgitating trash because they don't have to innovate because of this infinite copyright and this idea you can continue to exercise control over everything that you've ever put out into the world.

If our patent system functions like our copyright system you wouldn't have 90% of the tools you use to create your content. And I don't have any great love for our patent system that has been twisted a bit but it has not gotten to the extent of the idiocracy that we have allowed the copyright system to turn into. Content creators are the court jesters but somehow it has been twisted into them thinking they're the king and so they're going to make the rules and edicts on how their content is used after it's given away.

So absolutely your thoughts are only yours while they remain in your head. Once you share them society is okay with the bargain but not the bargain that you twisted it into. You're attempting to control and destroy a culture by thinking you can control other people and how they want to use the content you're creating. The hubris of someone like that is mind-boggling.