I just drove 400 interstate miles today, so I had the opportunity to try several locations. I think I have found the best one for me.

I placed the suction device on the driver side window nearly touching the "A" pillar at about eye level for me. Looking at it is the same eye movement as checking the side mirror and the boost gauge, but neither is obstructed by the GPS. Also, I lose no windshield visibility and very little on the side, as the "A" pillar is right behind the GPS. Left hand is free to select features on the screen

I run the power cord from the center console 12V plug across the steering column and leave some catenary on the left side. So, I can open the door and exit without unrigging anything. Also, the cord does not affect manual gear shifting nor does it become entangled with my knees.

It works for me.