Craig,
If you listen to the most recent podcast on this website, Dan Prescher interviewed me for Q&A, and this was one of the questions I addressed. I explained how to find a detailed description of driving through Mexico to Belize. It’s a big time and cost commitment to drive all the way from Canada to Belize. If your main goal is to be able to drive around Belize to check it out, it would be more efficient to fly here and then rent a car for a week or two. The cost isn’t cheap, but in the long run it may end up being less than the cost to drive all the way to Belize,through Mexico. Also, driving through Mexico does have some risks.
I’m not sure if you realize that you won’t be able to bring your car onto Ambergris Caye and Caye Caulker, two of the most popular areas where expats live in Belize. So you would need to leave your car somewhere on the mainland while you visit the cayes. You can rent a golf cart on Ambergris Caye, but won’t need it the entire time. And you won’t even need a vehicle at all on Caye Caulker. It’s small enough to cover on foot, or on a bike.
But if you do want to drive through Mexico at some point, there is a very good, detailed explanation (5 pages) written by someone who has done it many times, on the Expat Exchange website, in a post. So join the Expat Exchange website, http://www.expatexchange.com. Then open the Belize section. The most helpful post I’ve found was made by a person that goes by the name BelizeIsIt. He posted the driving through Mexico details on February 18, 2014. It’s worth it to copy and save his detailed instructions.