I've used the suction cup method but I mounted it under the dash with a stick on disk for said cup. I then ordered a different elbow attachment for my Garmin which positioned it in a way that the top of the screen was just above the bottom of the dashboard itself. I personally enjoyed not having it block any of my windscreen tucked away. Happy to mount and post a pic if you wish.
I have done similar, works well and doesn't obstruct my view through the windscreen.
