Oneplus One holder for use with magnetic car vent mount

I made this thinner since it's not needed to be as stable as a bike-mount - furthermore I added the possibility to add a metal plate for a 360° turnable magnet-holder

For use with a magnetic vent mount including a round metal-plate (up to 4cm)
Black part is the metal-plate of the following item: http://www.gearbest.com/car-decorations/pp_227923.html?wid=21