I've seen them all. When I was in Africa I saw them with Canadian plates, Quebec plates. I saw them running around with Texas plates, and then they would hang their own national plates on it.
In 1998 I did a peacekeeping mission over in Bosnia with the RCMP. I saw a lot of vehicles from Ontario and Quebec being driven around the country with Canadian plates on them and no questions asked.
There are a lot of rules and regulations that we experience here in North America that do not apply in these parts of the world, especially in West Africa. Vehicle registrations are hard to do. If you talk to any of the Canadian embassy people or the RCMP LOs in these countries, if you give them a VIN number and ask them to check it out to see if it has been registered in Nigeria, the Ivory Coast, or Ghana, they'll say it's nearly impossible. The whole system of registration is not there. So running around with a Canadian plate on a vehicle is quite common. In talking to West African authorities, I've sometimes heard it even becomes a status symbol.