@Dante, why do we allow them to sell here? Well would you prefer a system like say Russia in the 70's? You can pick a red Lada or a blue Lada and wait for 2 years for one. Why do we allow strawberries to be sold here in January? Should we place high duties on strawberries in June when they're growing here? What about Pineapples, should we even let them in to the country? They look funny.
Yours is a typical Trump style attitude based on ignorance. Lets say only cars built in Canada should be sold in Canada. Let see, Chrysler mini van, Dodge Charger, Dodge Challenger, Buick and Chev 3 models, Toyota Corolla, Maybe 1 other Toyota product, and 2 from Honda.
There, happy with those limited choices? 
Now if WE couldn't export those  CDN built products our domestic market couldn't support the mfg base and costs, so maybe we'd have 1 or 2. 
Would that be a red Corolla or a blue Corolla for you?