Let me say for starters that I'm no authority on this subject whatsoever, aside from importing a few US cars into Canada, so I'm kind of completely talking out of my arse
but that said, I doubt CDN cars are US DOT compliant, because we have to have daytime running lights, whereas US cars don't. (though I think they're introducing that in the US now, aren't they?) We've got a whole slew of (mostly inane) vehicle regulations that the Americans don't.