Volvo EX30, sunvisor clip-on sunglasses holder.

Print it out of for example PETG. It will withstand heat pretty well and can flex quite a bit when attaching it to the sunvisor.
You might want to add some brims depending on how well your buildplate sticks. 
It's important to keep the printing orientation for best strength and flex.

-Unhook the sunvisor and turn it a bit for some more space.
-Then hook the rounder side of the holder to the sunvisor edge furthest towards the windshield (when folded into the default position. Like in the photo).
-Then finally grab the other end of the holder (that is a bit thinner and pointier) and bend it carefully whilst hooking it around the inner edge of the sunvisor.

My cheap PETG's could bend enough without any problems, but if you have some more brittle materials it might crack.