Hi RollyB,
Welcome to the LaptopGPSWorld forum.
Great question. I'm sure many have thought about traveling in Mexico and wondered if there was much Mexican map data.
IMO, the answer is "yes". There is both street level data and points of interest in Mexico. To be honest, it isn't quite at par with the coverage for the US or Canada but wheneven I've shown it to people they've been happy to see what we have.
I've attached a couple of screenshots but my recommendation is to download the 60 day free trail yourself and see if it meets your needs.