BTW, did they do this with just a log book entry? I assume you didn't go for a field approval on this.
Correct?

I was afraid you'd ask that....

Yes, the shop in Waterloo did it with a log-book entry, with the
blessing of the Des Moines FSDO.

The other shop I contacted (in Galesburg, IL) was adamant that they
could NOT install it without field approval from a different FSDO.
Needless to say, they didn't get my business.

I hate how anal some FAA people get. The AirGizmo is a piece of plastic
that allows my GPS to snap in place, holding it securely, no different
than a yoke mount (and probably safer). Why, just because it's
mounted on the panel, anyone thinks it's a "major modification" is just
beyond me. Thankfully, the Des Moine FSDO guys are apparently blessed
with superior powers of common sense.

Anyway, the moral of the story is: Shop around. Not all FSDOs (or
shops) are created equal.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"