This is a two-part adapter that mounts on the speaker grill in the dashboard of a Porsche 924 or 944 phase 1. Remove the grill and use zip ties to fasten the two pieces together.
It works with SPConnect phone cases but can probably be remixed to fit anything else.
Parts are oriented to be printed without support.
EDIT : added STEP file
The author marked this model as their own original creation.