1999 Cabin filter conundrum
 

Need help with barn find please.
I have no idea where or if this part was installed under the passenger side cowl above the blower motor. It was found loose near the shredded cabin filter when I was cleaning out all the critter nests and such. There is no part# on it only some lettering, "TRW 1" and "SAE PP". It apparently vents air for something but I cannot figure out where it clips on at. It is the same width as the filter and about half as wide.
Thank you for your consideration.https://cimg0.ibsrv.net/gimg/www.bui...9dc69744da.jpg
https://cimg2.ibsrv.net/gimg/www.bui...763c908479.jpg

Good luck on this one. But is filter replacement done from under dash or I know Mustangs (apples/oranges) are replaced from engine compartment. Maybe this is the same and parts just dropped or pushed through, worth a look anyways?

Thanks for your reply Rich B.,
It is definitely under the hood, there is a two piece cowl the wipers rest on, beneath that you can see the slot for the filter where it rests directly over the squirrel cage. Darn rodents probably got it loose building their nests.