so is there actually bad cai's and good cai's, or is it just the filter that matters? how will i kno a good one from a bad one? also does the sound of the generic cai change from the aem sound? im really loooking for a little more pronounced sound coming from the front of the car.

also,what does the cai actually change from a stock engine? if its just a tube why doesnt honda make them that way? is it just the placement of the air filter?
(minimal mech knowledge), but first car=many experiences that will help

where do i pick up k&n filters? how much will they run me?