Replacement Cabin Air Filter? Options

[Rider]

I've read that there's no actual "cabin air filter," but that there are two foam things under the black plastic piece that's under the wipers - one for air from outside, one for recirculating air.

Does anyone have info on replacement filters/foam pad things, like where I can get ones made for the car? I don't want to have to buy foam/filter pieces, cut them out, and rebuild the stupid things.