Both the OP and the reply seem a bit over-the-top, but it's a fair call to say that the goal was changing the subject from "who owns the tractor" to "think of the children!"

People repair stuff they own all the time, and if they do a bad job of it, they are liable for any damages caused. All that's really needed here is some clear way to indicate that this factory-issued X has been modified by the owner to be an X1 model. End of story.

We can't continue down this path of people developing software and somehow in the process picking up vast quantities of physical goods that buyers think they actually own. Not only is it evil, it's nonsensical from the viewpoint of the average informed person. The only reason it's worked as long as it has is that most people aren't informed enough about it. Tractors might be the straw that breaks the camel's back on this issue. People don't think much about the inner workings of their phones, but Joe Farmer fixing his tractor is a concept most folks don't have difficulty getting their head around.