GPS Maps for Mexico

I will echo the advice of keelhauler1 above - no GPS promises to take you on the correct route. The route the GPS chooses is often not the best route. We constantly design our own routes by putting in stops along the way. You absolutely need to check the entire route in detail before you move one inch. Sounds like what's the point? Why have a GPS if it does not go where we want? Because once you plan the route you just follow the GPS as you go down the road and you will know where to turn and where you are. We swear by Microsoft Streets & Trips for planning our routes and then use our Garmin using the same planned route as we go down the road. Great tools are only as good as the person using the tool. A skilled craftsman tells his tools what to do.