Look, I get it. It’s probably OK to not replace your dust and pollen filter every 30 000 kilometers as called for by the maintenance schedule. In not-so-dusty environments you can probably stretch it to 60, maybe even 100 000 kilometers.
You can’t, however, stretch it to “never”.
R100 and Tanya’s car gets fresh air again instead of effectively being stuck in “recirculation” because of a very dirty filter.