Planet Audio P350MB Mouting Bracket

This is a universal hanging mounting bracket for the [Planet Audio P350MB](https://smile.amazon.com/Planet-Audio-P350MB-Multimedia-Stereo/dp/B08KRRKQXF/), and very likely fits additional 1-DIN head units that share the same retaining ring clip mounts on the sides.

I designed this to be able to mount a 12v car radio under the workbench in the front of my enclosed car hauler, though it should be useful for just about anywhere you'd like to be able to hang a radio.

The FreeCAD project file is included in case anybody would care to adapt this bracket to fit other devices or mounting styles.