Air Gizmo panel mount for GPSMAP 196/296/396

Anyone out there have an Air Gizmo panel mount for their portable GPS
device?
I've been searching high and low for official word on whether or not
such an installation would require a field approval. I've heard yes and
no from various sources, including some on this group.
I ran across this tonight while searching the FAA's website:

"VOLUME 4. AIRCRAFT EQUIPMENT AND OPERATIONAL AUTHORIZATIONS 8400.10
CHG 39 12/23/05

51. FAA APPROVAL OF GLOBAL POSITIONING SYSTEM (GPS) EQUIPMENT AND
OPERATIONS.

A. Portable Units. Portable GPS receivers can only be used as a
supplemental aid to VFR in conjunction with an approved primary means
of navigation. All portable electronic systems and portable GPS units
must be handled in accordance with the provisions of 14 CFR part 91, §
91.21. The operator of the aircraft must determine that each portable
electronic device will not cause interference with the navigation and
communications systems of the aircraft on which it is to be used. Yoke
mounts usually sold with a portable GPS unit must be mounted as to not
interfere with the operation of the aircraft controls. Permanent mounts
and externally mounted antennas for use with a portable GPS unit must
be installed in an FAA-approved manner...."

We've determined that 14 CFR part 91.21 is not a problem as the device
does not interfere with NAV/COM on our aircraft.
As far as I can tell, according to 14 CFR Part 43, Appx A(Preventative
Maintenance), removing and replacing such a device would qualify as
preventative maintenance but the citation above is the only place I've
found anything pertaining to the actual INSTALLATION of such a device.

So my question is, what does "installed in an FAA approved manner"
actually mean?
Do they really mean Field Approval, or are there other FAA approved
manners in which to go about this installation?


Brock Boss
Student Pilot/Confused Co-Owner