I hear they work fine and dont hurt the airflow too bad (K&N claims it doesnt affect it at all). My car has a fender mounted CAI and I haven't had any problems with water near my filter just because of how much plastic is around where the fliter sits, its pretty well protected, it gets dusty but my filters never been wet (granted I'm from arizona and we get one rainstorm a year.) If you live in a wet state it probably wouldnt hurt. K&N probably has the best one, though I believe their oiled filters keep water out well enough to not need one.
Thank you, I’ll check their’s out. Wet State Oh Yeah, Sunny South Florida, so when it rains it usually pours! So mine too goes into the fender, all the way down, and when it pours real bad on the highway I’v sucked up a little, bogged the engine for a second so I got off the highway and drove real slow without a problem. Over this winter I cleaned and re-oiled the filter with K&N recharging kit so I’m hoping some fresh oil on it will help. A Jeep owner told me about the filter cover so I figured I would ask. Thank you again!