I want to make a simple bracket, similar in shape to
It's a one off so I'm not wanting to go to expense of heat guns, though hair dryers are available.
The idea is to slip it over the phone+case then use a standard car mobile phone holder to mount it in the car. As it is the folded back wallet cover of the case doesn't allow the phone holder to grip properly. The bracket therefore needs to have a bit of flexibility to enable the sides to be squeezed in a little when clamped in the phone holder.