We are still in the process of selecting a new 4x4, with the Grenadier as strong contender.
I have previously mounted this type of camera/rearview mirror as a direct replacement for the original mirror, eliminating the rubber straps so it looks very OEM.
I got my bracket form Amazon UK, there are a few variations and you need to see which ones are suitable (if at all) for the mirror you select (spacing of screws) and the original fitting for the mirror (e.g. on the windscreen) .
This is the link to the one I purchased:
DVR Mirror Bracket arm
As I say I am not sure how the original mirror is connected on the Grenadier, however this approach might be viable?
There is no wobble at all as the mount is pretty strong and quite secure/stiff on the various ball joints.
Hopefully that might provide some other options.
Thank you