I've got one on my car. I think it probably filters better than the HKS "shroom" filter. The Greddy seems to have tighter fibers. I really don't know how to clean mine, I periodically knock it out, but upon close inspection there is always tiny pebbles of sand and such stuck in it. I guess you could wash it or replace it , they are probably $20 or so ( I would hope no more than that) . A K&N with a cold air box is probably the best bet though