Is anyone else smelling a conspiracy of the oil industry lobby?
What other reason could there be for legal obstacles to introducing efficient vehicles while it's apparently no problem to drive around in gas guzzling SUVs, Vans and muscle cars?
50 different legislations in 50 different states probably don't make this any easier either.
As for the Canadian question: my guess is that it's to small to be relevant. If they can't sell Diesels in the US (for whatever reasons), Canada won't get them either. If anything, the model choice in Canada is smaller than in the US.