Newbie here and became a paid member to get POI data. I have a Garmin Nuvi 2415.
Perhaps my experience will help others after searching the forum and not finding the answer I needed. After a bit of experimentation:
1. The 2415 will not work with MP3 files, I then tried the WAV files and with the SOX.EXE file in the Garmin/POI loader folder it works OK.
2. I've found that cameras are not unidirectional. ie. they are alerted on both sides of the road incorrectly - dissappointing - I would appreciate a comment on this and whether others have found the same.
3. Files are only overwritten if you use the same filename. As far as I can see you can have many POI's on you Garmin just name them differently and enable/disable on the Garmin as required.