I mean I don't think a lot of things on cars need or sometimes even can be improved other than the battery tech. Producing nearly the same body and control systems for 20+ years could save on manufacturing costs and could save customers on repair parts costs.
Nobody jumps in a 2002 car and bemoans the fact that it lacks lane drifting warnings or that the door handle doesn't have some overengineered mechanism, it still does everything they need and more without difficulty. 90% of people's complaints would be, if not so directly, "It was made over 20 years ago and parts are worn and sloppy" which almost all disappears if the exact same car still rolled off the line today and was new. It is also a chance for iterative improvements when engineering flaws are found, like cracks on hard wearing components or early bearing failures.
But that doesn't seem to be the kind of thing Tesla ever planned to actually attempt so it doesn't help them now. It may have been brought up once or twice before as an idea but nobody has ever mentioned more robust tooling in their plants to plan for it, repair parts are still super difficult to come by, and there have been substantial changes of component design between years that make them incompatible and not just improvements.
Nobody jumps in a 2002 car and bemoans the fact that it lacks lane drifting warnings or that the door handle doesn't have some overengineered mechanism, it still does everything they need and more without difficulty. 90% of people's complaints would be, if not so directly, "It was made over 20 years ago and parts are worn and sloppy" which almost all disappears if the exact same car still rolled off the line today and was new. It is also a chance for iterative improvements when engineering flaws are found, like cracks on hard wearing components or early bearing failures.
But that doesn't seem to be the kind of thing Tesla ever planned to actually attempt so it doesn't help them now. It may have been brought up once or twice before as an idea but nobody has ever mentioned more robust tooling in their plants to plan for it, repair parts are still super difficult to come by, and there have been substantial changes of component design between years that make them incompatible and not just improvements.