The point is that the designer gets paid once, at the time if design, and the car companies make as many copies as they want without paying an additional penny. Anyone who buys a car never pays an extra penny to the designers no matter hire many times they use the car (analogous to watching a movie or show multiple times).

But let’s take you’re argument- that it costs money to make a copy. All modern cars are filled with software - entertainment, operations, video processing, communications, autopilot. Afaik, no programmers at Ford are getting residuals for the number of times their startup menu plays, or the fuel injectors modulate for a different mix of fuel.

The crux is how these creators get paid - as a fee, or with a speculative, contractually-agreed rate. We’re somehow appalled when one field doesn’t get residuals they want, but other fields never get them at all.