I am used to the speed being displayed right in front of me, so I designed an iPhone XS Max holder that clips snugly into the air vent. iPhone Speedometer software displays speed, maps etc directly in the line of sight.
Matter Hacker NylonG Nylon
Printed at 250C using minimal support (ABS)
I printed the clip and the iPhone holder separately to minimize the use of supports and then glued both parts together using epoxy glue.