I would rather have the only car with an audience of 50 buyers, than one of 2000 cars with an audience of 10000 buyers. With the current exchange rate this is a gold mine that will slowly but surely be capitalized on. It used to go the other way (Canada to US) but now, it is far more profitable to bring them to this side of the border.
In cases where the manufacturers void the warranties you just buy an aftermarket Warranty like Secure Drive. On most cars you can pick up 3 year bumper to bumper coverage in around $3000 mark, and on a vehicle where you save 6-8000 grand, you are still way ahead of the game.