UPDATED with v2 - June 9th, 2023
This is simply a phone cable guide that slides onto the HVAC vent in my 2023 Subaru Forester. I needed something to keep the cable out of the way of the infotainment screen because the cable would block the map when I had my phone in the windshield-mounted phone holder.
I've included the FreeCAD models so that you can modify it to match your vehicle based on its measurements. This one might work for you as-is. It took 7-minutes to print two of them at 0.3mm layer height. It's printed in PETG because it's going to be in a hot car.
The v2 update increases the thickness where the “fingers” will flex when slid onto the vent. The original version lost its grip on my vents because the plastic relaxed a little in the heat on a hot day. I also closed the gap between the fingers slightly to increase grip. So far, the new version hasn't lost grip!
The author marked this model as their own original creation.