Thought I would revive this thread to share where I ended up putting my dash cam.
The windshield was too obtrusive and showed way too much from outside.
I decided to mount the dashcam with velcro to the actual plastic housing just below the rearview mirror.
It turned out great. The camera itself gets a perfect view of the road. The camera is out of my field of view. I can just make out the very bottom below the rearview mirror and from outside the car it's a lot less noticeable.
If you are asking which dashcam?What kind is that?