A couple of links for export of used vehicles from US to Canada
 

Yes it looks complicated! But here are a few links that detail how to export a used vehicle from the US to Canada.

https://www.census.gov/newsroom/blog...DpB3mumJue1YHQ

and,

https://www.cbp.gov/trade/basic-impo...eeMdi2bXDFSVP0

It is worth looking at the inbound rules for import to Canada as well as the outbound rules from the US:
https://www.tc.gc.ca/en/services/roa...g-vehicle.html
http://www.riv.ca/ImportingAVehicle.aspx
Compliance with both the outbound rules from one country and the inbound rules of the other is required.

An article in more commonly understood terms rather than "officialese".
https://driving.ca/auto-news/news/ho...-s-into-canada