After using a clip-on air vent mount for a few months, I came across a much more elegant and solid solution that I wanted to share. It uses a device from ProClip (sold in the PriusChat Shop) to create a stable surface to mount on and a tilt/rotate spring loaded phone holder from Arkon. The ProClip protects the back of the phone from being excessively heated or cooled by the air from the vent whose louvers remain fully adjustable. http://www.proclipusa.com/dashboard-mounts/vehicle/toyota/prius/2016-2017/proclip-center-mount-855200-13997.cmsv?p_leftorright=0 Universal Smartphone Adhesive or Drill-Base Mount VSM Adapter Kit for Car Installation: Arkon.com ProClip was kind enough to send me self tapping screws since the nuts and bolts included with the Arkon were inappropriate for the application.
Because I did not use the adhesive tape with the mount itself, it can be taken off by squeezing the horizontal elements. I don't think it is designed to that on an ongoing basis.
