To find out about the process to import a US car from the United States to Canada, you should contact the Canadian Registrar of Imported Vehicles, www.riv.ca. This Canadian agency should help describe what needs to be done to bring your vehicle across the border and into Canada.
As for registering the vehicle in Ontario, Canada, this would be done through the Ministry of Transportation, www.mto.gov.on.ca. The MTO states that vehicles on Ontario roads must be registered, insured and maintained to meet certain basic standards.
Ontario has compulsory automobile insurance laws. Before you can attach plates to a vehicle, the vehicle must be insured. Private companies provide insurance coverage in the providence of Ontario. All vehicles must be insured for third party liability for at least $200,000. For more information on Canadian Insurance laws view our article The Basics of Canadian Car Insurance.
Americans that move to Canada and become residents there are able to register their vehicle by following the import and registration instructions. Not all cars are allowed through for importation and registration. The Registrar site listed above has a link to the list of vehicles admissible from the United States, so be sure to check it out and make certain your automobile is listed.