No approvals so not legally installable other than in a homebuilt/ML type, as far as I can see.
Some nice panel mounted versions
That is the problem with all things aviation. I don't see why for "VFR use" things like fitting of FLARM, panel mounted GPS's cannot be deregulated, so that anyone with an ounce of common sense can fit the thing themselves?
After one star annual, when leaving the zone our radio failed, despite having just had the radio annual done. I had to fly back home non radio. We investigated it ourselves and found the centre core of the antenna coax had come unsoldered from the back of the radio tray connector. We resoldered it and it has been fine ever since - that was 2+ years ago now.
As for fitting panel mounted gadgets for VFR use I know I can fit one, do all the wiring to a high standard, and for it to be done as well as any avionics shop........
With regards to GPS's - if I replaced our panel mounted GPS with a new one, wired into the same power supply connections and same antenna connections, what paperwork if any would be required?