This is a pretty straight forward vent grill for the extractor hole I cut in the hood of my Exocet. Nothing I found on the market would really work off the shelf in my car's application so I figured that I'd have to design it my self. I place it here for anybody else who would like to give it a look/try on any of their own projects. (I make no recommendations as to the best place to install an extractor vent on your car, your mileage may vary.)
I provide two versions of this part, the first version does not have a leading edge lip meant to induce a low pressure area over extractor hole as I have installed an aluminum angle lip for that purpose in my own car. The second version DOES have this feature.
Since my printer isn't large enough to print the whole piece as a monolithic object, I had to split the model in two and print right and left sides, then glue them together post printing. This works fine.
I have included monolithic and left/right stl files for both versions of the extractor grill.
The prototype print shown in my included photos was made using PLA, for durability and part longevity, I recommend printing in ABS, PETG, or nylon. My final print for this part will be made using nylon.
I would not recommend placing any plastic vent in an area of expected extreme heat such as, say, over a turbo charger.
I drew this up pretty quickly using Fusion3D based on the dimensions of the hole I'd cut out in the hood of my car between the radiator and engine block. it's meant to fit nicely into the center bulge.