Originally Posted by BobGee
Drive through one patch of dusty road and it will look like that in 30 seconds.
I pull them, shop-vac them, then slap them right back in. I might change them every ~2yrs or so.
FWIW, be careful with the inexpensive eBay replacements. I bought an "exact fit" CAF for my 2008 Hyundai Santa Fe on eBay and it wouldn't fit. It was close, but not close enough. Returned it and picked up a replacement at CarQuest.