I can only say that quotas that are not company-wise and product-wise can work with countries that supply commodity products, or plain vanilla products, to the U.S. like South Korea, where the quantities are very small.
In the case of Canada, we have contracts, one-year contracts with auto companies in the U.S. You cannot suddenly in the month of September say your quota is over. You need to plan for the whole year. The company needs to know. The customer needs to know. You cannot have a free-for-all system. It has to be product-wise, and it has to be company-wise.