G'day poncil, welcome to GPS Power. In some older units the detail maps do go in the unit's Garmin folder, but in your daughter's 54 they will go in either the ".System" or "Map" folder on the unit, or in either "Garmin" or "Map" folder on a microSD card. Naming of the map img file depends on placement, but in Map folder for either unit or card it can be <anyname>.img e.g. "AUNZ_CNNT_2016.20.img". Make sure the new map is unlocked, use [Only registered and activated users can see links. ] if not sure. Best to read up if you need more info, it's all available in the [Only registered and activated users can see links. ].