The next things to mount are all the remote boxes. These don’t require a front end on the panel or can be operated via the G3X Primary Flight Display (PFD).

This is where I decided to mount the remote transponder. It mounts in a tray and I put the tray under the channel I added shown in picture one. This is an old piece of scrap from my Sonex. One side of the tray will attach to it and the other side to the rib next to it.  It is clamped in position in the second picture. You can see it from the side in the third picture.

The last picture shows it peeking out above the rudder pedals. It slides in and out no problem.