I have had my RX 65 for a couple of weeks now and am trying to find the "perfect spot" also.
Here's my problem, I have a Toyota Matrix and right below the mirror is our states inspection sticker so to mount it in the middle of the windshield i have to put it below that sticker. It seems to work great there but it is in plain view, which I do not like.
I am currently trying it a little to the right of the mirror just below the black tint dot's this car has.
My ? is does any body know or has tested mounting it slightly off center but up high to see how that effects it. Also I am wondering how mounting it behind these little tint dots in the window would effect it. They do not seem metallic.