CBSA will generally allow goods imported (or shipped) valued up to a max of around $200 (as must be stated on importation paperwork) to proceed unimpeded. For something like wheels/rims, they're large, probably heavy, and will be "noticed" based on that. If the value of the goods exceeds $200 (probably will in this case?) they'll hold them at the border, and the shipping company will/may pay the duty/taxes owed on your behalf, but will stop the shipment there waiting for you to reimburse them. I speak from experience, but this has been my experience. Yours might be different. Full disclosure, I live about a mile from the US border and cross, and shop, regulary there. I also have stuff shipped from there to me, and have some experience with the process.