I'm probably paranoid about the possibility of contamination of the brake fluid in my '05 ABS modulator reservoirs, but to avoid the possibility of any dust ever finding its way in there I installed a 1/4" plastic in-line paper fuel filter in the breather hose just behind the battery, above the plastic guide ring. I would have installed a miniature dessicant type filter if I could have found one, they also trap any moisture. Being an Ozzie, I don't know whether this is a ghetto mod, farkle or what it is, but that's what I did. Looks tidy and ensures any displaced air will always be clean, not that there's ever actual flow through the tube. What's a Farkle anyway ? I bet we've got a word for it, but probably best not to print it here.