Originally Posted by M3W55
A number of people do this

[Linked Image]

[Linked Image]

Long headless bolt - notched plastic ball (TomTom size; larger for Garmins).

Are you satisfied with this solution?

I installed this RAM mount for my Garmin Zumo.
I use my Garmin in my Morgan and on my Kawasaki motorbike and in various rental cars.

Only on my Morgan I notice poor GPS precision whenever I am between mountains or high buildings.
On flat terrain it works fine - as ususal.

I suspect that the metal dashboard blocks half of the sky so that the Garmin can't calculate a good position fix.

An external antenna might help, but I haven't tried it yet.

2016 M3W