I have this issue on my Pace.
For a quick summary of the issue that some of us have and are trying to describe:
Has nothing to do with dual vs. single pane windows.
Has nothing to do with dashboard being covered, etc.
Has nothing to do with mirror itself.
Has nothing to do with flat vs. curved windshield (although that may be another problem)
Has EVERYTHING to do with the use of flat glass on side windows. It's one of many reasons that auto manufacturers went away from flat glass on side windows. I had this same issue, to a lesser degree, on a 1975 Toyota Landcruiser, the old original "FJ". It had completely flat glass for both side windows, as well as the windshield. My old VW's back in the 60s had the same thing. In more modern passenger cars you can frequently see a reflection of the dashboard. This is because of the curvature of the glass. Pretend the glass is a mirror and this might make more sense.
To give another description of the problem, imagine driving at night and passing a truck travelling in the lane to your right. If you were to watch out the passenger's window, you'd see the truck "sliding" backwards relative to you.
If you have this glare problem that some of us have, in the above situation, you would see a perfect reflection of said truck "sliding" backwards, on the DRIVER'S side window. It's a reflection, certainly, but it can be very disorienting for some. It makes it looks like you're passing two identical trucks, one on each side of you.
Btw...my navigator can see the same exact thing happening in reverse on HER window, that being a reflection of everything happening outside of my drivers window.
Problem is much worse at night. You have to learn to look "through" the reflection to what's really happening, which is possible, but not desirable. When this is happening, it renders the mirror almost useless.
I believe the "vane" installed at roughly a 45deg angle from the windshield A pillar back towards the driver's seat is the only solution to this. It has to extend far enough back to block the reflection on the area of the window that you look through to see your mirror.
And it should not be transparent. You can try this out with just cardboard and duct tape to see if it works for you, which it will
There will still be reflections on the window, but NOT the area that you look through to see your mirror.