OK How it works is.. depending on wheather it is a private sale or not and the province you will have to pay either one or two taxes on the car. Then you will have to get the gages and a bunch of other stuff changes to US styles (cost you a few hundred CND). Then when you go back over the boarder you have to pay duty on the car BUT you get the taxes back. So bascially they cancel each other out.
Emisions, gernally Canadian standards are WAY higher than US. Then again this depends on the province and location. Toronto's standards are inline with California's. However, our regulations on gas are tougher so either way I doubt there will be issues with emisions.

But then again, STOP STEALING our cars! lol :twisted: