I just wanted to add that given the strength of the Canadian dollar (which worth slightly more than the US dollar nowadays), there is a flood of Canadian buyers crossing the border to buy a new/used car down south...to combat this, car manufacturers, since they apparently have the power to dictate whether or not their cars can meet US/Canadian standards, are registering their cars as not being able to be imported/exported across the border...A LOT of people have been running into this problem lately...especially for new cars, but used cars are also being affected too...no real "concrete reason" was given by the manufacturer, other than a very vague reply saying the vehicle does not satisfy Canadian safety standards...which I think for the most part is bogus...
I have been following this topic on a Canadian "hot deals" forum regarding importing cars from the US to Canada...I think if people on this site cannot help, you might be able to get some pointers from these guys...they seem to have quite a bit of experience, but they seem to be mostly dealing with new cars...but I see a few threads on used cars...furthermore, they are quite knowledgeable about the import law/process...
http://www.redflagdeals.com/forums/showthread.php?t=307601