Quote Originally Posted by fc321 View Post
Im starting to consider the idea of cutting away the outer border of a used filter and staple a few over-lapping coffee filters. This should kept the debris out but it wont help with the foul smells. But you can prevent "stinking" a/c vents by remembering to turn off the snowflake (on the air conditioner) a few blocks away from home and let the vents dry out with dry air. Its the wet droplets left behind in the a/c vents that grows the mold and bacteria that is responsible for the foul smells.

Actually if we are just looking for a "screen" then maybe a combination of window screen + coffee filter? Or how about a piece of cotton T-shirt?
I can's say that I have experienced the foul smells coming from the vents, but it's probably not as humid in Wisconsin. We obviously live in different climates. I seldom use A/C to begin with. If it's a bit warmer out, I prefer driving with the windows open.

I just check my cabin air filter from time to time. Sometimes, I just blow out the dust with an air compressor & re-install it. At times I just replace it. As long as cheaper cabin air filters (under $5) exist, I don't see the need to spend more for them. I also don't see the need to create an alternative.

If you come up with sometime that works really well, however, it would be interesting to see it.