[quote=spdrun]Not really — smog has decreased even in non-smog states. Cars get replaced by attrition anyway and post 1990 or so cars all have catalytic converters and electronic fuel injection.
Old, old cars are really an edge case and not subject to smog in most places anyway.[/quote]
In CA, vehicles which are 1975 model year or older are not required to be smogged (or Diesels 1997 model year or older):
