Yes I mean classic cars are dirty but there are very few of them, most being used only seldom. However there are 10s of millions of >2 ton hunks of metal being

Yes I mean classic cars are dirty but there are very few of them, most being used only seldom. However there are 10s of millions of >2 ton hunks of metal being used to haul mostly 1 person around, with all the consequences that implies: pollution, noise, space for roads, space for parking, traffic fatalities, etc. That's a real problem.