There is a simple (and easily understandable) reason why a person cannot get insurance coverage for multiple countries that are on different continents than the continent where an insurance company is based.

To be eligible to underwrite insurance coverage, an insurance company has to go through numerous rather complicated, expensive, and time-consuming processes to register and be approved and accepted as an insurance provider in any given country. If there is little customer demand for such services - as is the case for an Australian company to provide coverage in Europe or Asia, or for a Canadian company to provide coverage in Mexico or Europe - it just doesn't make sense for the insurance company to go to all that trouble.

In some markets, such as Canada/USA, the EC countries, Singapore/Malaysia, and similar locations with substantial cross-border vehicle traffic, treaties, protocols, and supra-national agreements enable underwriters approved in one country to provide coverage for vehicles when they are used in the neighboring country. But such agreements only exists where there is a substantial demand for such services.

There are underwriters who offer global or near-global coverage in specialized markets such as aviation or marine, where there is a demand for global coverage. But there is very little demand for global coverage in the automotive or motorcycle market.

You could, I suppose, go to an organization such as Lloyds of London and obtain global coverage for a vehicle if you were willing to pay enough money, but I suspect that even if you found an underwriter willing to take on that challenge, the cost would be prohibitive.