Just wanna share this with you guys whom may look for a low cost alternative. It's not my 3D model but a search result from Thingiverse. Lexus LS430 seat air filter holder/adapter by romas69 - Thingiverse

 

This filter is likely much more restrictive than the oem filter due to its purpose being to catch fine dust, pollen, allergens, etc. The oem filter is just there to protect the fan, so it should let much more air through without putting a stress on the fan. Has anybody used these and can confirm if the airflow feels the same or worse than the oem filter? A clean filter, though. Not like the ones in these photos.