Even then, a EURO5 diesel still makes quite a stink. Of course, even an EU6+OPF gasoline car still puts out air akin to a dying dog's fart.
ICE vehicles just can't go away quickly enough (and we should aggressively get stinky vehicles like everything pre-EU5 and loud vehicles like motorcycles and scooters off the road first).
I'm not huge on regulation, but if anything MIV is underregulated. Even in the EU anything that was street-legal at some point in the past 70 years is grandfathered in, nevermind that illegal vehicle modifications - if caught - at most earn a slap on the wrist. That's enormously dumb and doesn't fly anywhere else.