Was trying to figure out why I had a metal backplate and extra strap after installing my Argus PT and Solar Panel, so you're request has been answered. Newer Solar Panels seem to have a back plate, screws and strap that now let you mount the solar panel via Strap. Found this out after doing a DIY solution atleast I have a backup option now if it doesn't get enough Sun.

Doesn't seem to be mentioned in the Manual or anywhere...