Toyota Air Vent Lever - Open / Close - Tested w/ Mk II Prius (2004-2006)
Somehow I lost one of the levers that allows my vents to open and close. So if you spun the little "on / off" knob below the air vent, this wouldn't do anything.
Today I decided to take another one out so I could copy the missing piece. Attached is my copy. It took about one hour with millimeter ruler, digital caliper, and paper protractor to get it just right.
This will enable you to open and close your air vents if you have the knobs but not the little levers that grab the vents.
If you plan to 3D print, I urge you to consider between v3 and v4. I made v4 just to ENSURE it would grab the vent door and click on.
Also with my 3D printer I used the stove to soften the clip before pushing it into place (didn't want to take any chances) because it has to flex a lot!