I'm Canadian too. I maried a Colombian native and I have lived or traveled south of the USA since the 1970's. I bought motos Mexico, Colombia and Peru.
I have no idea where you get your info but CAA offers no insurance for any country, for any motor vehicules bought in Mexico, Central America or South America.
Wherever you buy a motorcycle, or just ride your own canadian motorcycle, you are required to buy insurance to cover medicals.
The motos that I bought in Colombia had full insurance coverage.
I'm currently in Mexico on a tourist visa, and I ride a moto that that is fully insured.
Concerning Peru, check out Toby Shanon.
adventure motorcycle tours in Peru and all South America - Home.
The guy has helped tons of travelers. It's by far the easiest way to buy a motorcycle, to buy insurance and even resell it to him.
It possible to buy motos in some other countries, I will let others who had done so in these countries to comment on that.
It can get complicated and expensive to buy a moto in Mexico and bring it over to South America because you will have to bring the moto to Colombia to cross the Darian Gap, by plane or by boat.