Which would happen a lot more frequently in this counterfactual.
One difference is the difficulties in making some 'parts' now. It's one thing to make a fuel pump for a 1950's car, quite another to duplicate a controller board, often with obsolete parts and secret software, that runs the convertible top.
Another is that a lot of parts are more monolithic than they used to be and harder to design/build. Look at headlight assemblies.
It doesn't help that with the increasing amount of software and electronics in a modern car (a Tesla being the leading example), the auto industry is acquiring the product lifecycle times and forced obsolescence of the PC industry.