Also why no rear fog lights in the US? They have been compulsory in Surope for years.
I never knew if they were illegal or not in the US, just that we don’t have them. My A4 had them (double pull of the dial), and most people with Audis here have no idea and drive around with them on. My 3 series, had the switch and bulbs (it was a US Spec import), but some older BMWs had a switch without the option, and bulbs missing (all you had to do was change the switch and put bulbs in).
I think people here would just use them all the time, since it would be new to most. But eventually people would learn.