I have a friend who's tried to purchase a new '12 GTR from the States because of the price differential. His search came to an end when he found out a new car must not only be registered to a valid US address, but the purchaser must also have a proof of residence. It was further complicated by the fact that Nissan Canada will deny the warranty if he cannot have the car legally registered for at least 6 months in the US, before he imports it back to Canada. Now, this might be different for BMW, but it's definitely true for some manufacturers. This seems to coincide with what the other 2 have suggested - you can't import a brand new car into Canada, not easily anyways.