This jives with my belief that street-legal cars should not be allowed to have any external or functional modifications. Basically, there is one version that was approved to be safe and street legal.

If you change the rims to be a different size, that alters several safety characteristics of the car, including its stability/balance and speedometer readings. If you add a spoiler, you’re changing its maneuverability. Even adding things like custom bumpers will change the fuel efficiency. Changing the engine or exhaust can change performance characteristics.

Basically, if you want to customize the car, you can change the interior. If you want to change other things, fine, but there’s no reason to let those things on public streets.

This would also have the advantage of giving “car guys” fewer things to be proud of, so presumably there would be fewer car guys going forward.

This sort of exists in Germany. Any modifications must undergo an inspection at the TÜV. If it’s deemed unsafe, you have to get rid of the modification.

This may sound good, but Germany is one of the worst countries in the world regarding bureaucracy, only surpassed by Japan I believe. These things don’t make life any easier.