I made this vent to allow more airflow for my Apple Powermac G4 case. I'm running a Ryzen 9 3950x with a 280mm AIO. It makes the case appear as if someone had just hit the eject button. I used a honeycomb design for the vent, reminiscent of the Peavey 5150 amplifier. The vent is held in place by friction from the CD-ROM bay door closing.

Max Airflow version deletes the honeycomb, and just keeps the CD bay door open.

Skeleton version removes the solid rounded edge continuing the honeycomb to the edge of the oem plastic. This one is my favorite (last photo).

Check out my profile for the zip drive vent as well.