I figured out how to do this using ArcGIS relatively painlessly, but it would be a lot easier if Garmin would allow for this functionality
I don't use the camera for action shots like it's marketed for but rather for documenting while simultaneously collecting the 'where' information (geographic file). Here is a link to a video where I use an aerial imagery file (not Google imagery) as a background for the track gauge. I also change the location of the gauge in the frame at 23:00.