POI's are it and I've loaded plenty. I would like upload / download .gpx files. Can't be done.
Dude, trust me and follow these steps. It works.
1. Install Garmin MapSource. If you do not have it, Google for a way to get it for free. For example: http://www.mydigitallife.info/2008/0...without-media/
2. Plug a mini USB cable into the back of the DNX8120 (the "TMC Tuner" port on the back of the unit) and plug the other end into your laptop. It will be recognized as a USB device (AVN3_NA) and Windows should do the "Found New Hardware" routine, installing the necessary USB drivers, however, you MAY still need to download the Garmin USB drivers from their site's support section.
3. Once the USB connection is establised, the screen on the DNX8120 changes to a blue screen screen with "USB connection detected" in the middle and two buttons at the bottom: "Garmin Mode" and "USB Mass Storage".
The "Garmin Mode" takes you back to the GPS navigation, while the "USB Mass Storage" mounts the Garmin unit as a drive on your laptop. To transfer your data to/from the DNX8120 using MapSource, DO NOT PRESS EITHER BUTTON.
Using this method, you can transfer waypoints, routes, tracks, maps, etc. to and from the device using MapSources "Send To Device" and "Receive From Device" menu items respectively under the Transfer menu.
Hint: I'd advise running a USB extension cable to the glove box or center console if you plan to manage data often.
If you're curious about loading additional maps, etc., the DNX8120 has a 2 GB drive with about 700MB free space.
Sorry, not trying to be a dick, but I do this all the time with various Kenwood/Garmin in-dash units and know many others who do as well. I'M RIGHT!!! There, I feel better.
Enjoy! There are some great free Topo and Trail maps, tracks, etc. available on the 'net for Garmin devices.