I don't use GPS in Mexico, nor are Mexican cars sold with GPS units. It does exist but, from what I hear, does not have the detail you might expect. One way streets are not shown, for example, and we certainly don't need GPS to find the main roads. A Guia Roji Gran Atlas serves our needs for highway travel and Guia Roji also prints detailed maps of all major cities. You can find them online.
I am bringing my own GPS unit with me and have read that the Garmin map isn't that good but that there are others that are.I am also going to Costa Rica and plan to use it there.Anybody know if there is a good one?