I didn't see a response back here (on this page), but I wanted to send the following information before I take a break for a few hours.
As long as your device is still working well (good battery life, works for current maps, etc.), you should be able to ADD maps for the area you want. BUT Garmin's maps for Central America are no longer available, so you will need to go with a 3rd party to get maps.
Since I did not see if there were specific countries you wanted to travel in or when you would be traveling, let me just refer you to one of the BEST places to get Central America maps.
Click here --> http://www.gpstravelmaps.com/gps-maps/mapsets/central-america.php
If you explore their site a bit more, you will see lower cost maps of smaller areas AND different ways to get the maps (download, on a memory card, etc.).
If you have the time, I recommend using a memory card, as installation is a SIMPLE process of putting the memory card in your device, powering up, and enabling and using the maps.
Please let me know what you find or if you have any more questions.
Take Care & Travel Safe, Greg A.