I'm not sure about your exact situation but when I moved to Canada I arrived from the USA in a U-Haul truck with my possessions, a month after arriving myself by air from the Caribbean. When I originally arrived I said nothing about possessions and it didn't matter when I finally brought them overland from the States.
As for the car, you have to import a vehicle separately. It was not on my goods to follow list but obviously... it was my car and they didn't question ownership at the border.
Bear in mind you must export the car and from the USA and then import it to Canada. Time consuming and will cost $.
HTH