Stringent regulations on classic cars would be one of the last boxes to check along the logical progression in the war on climate change. As someone said earlier, classic cars are a very small percentage of cars on the road. There are far bigger problems that would need to be assessed first, and to regulate classic cars right off the bat would be like spraying a burning house with a water hose thinking it'll make a difference, or to restore a crumbling building firstly by painting it, that way you at least won't notice the deteriorating walls. The only reason I can imagine classic cars would be regulated prematurely is so a politician can look like they're making a difference or an effort when in reality they hardly accomplished anything substantial. At any rate, I live in a small town where large trucks blow out black smoke (roll coal) and while this, too, is a minor problem in the grand scheme of climate change, it is marginally bigger than classic cars. I'll begin to worry we're next once these trucks are put under the political and ecological microscope. Until then, I'm more worried about ethanol ruining my car than I am about the government regulating it.