I have a K&N full CAI and i love it and the way it sits in in the bumper you'd have to go through some pretty deep water to suck up water it sits a good 3 to 4 inches inside the front bumper before the fender well and it's surrounded by for sides so it's not catching in water from the side and you can do like me and get the AEM release valve that when a large amount of water gets sucked in it stops the upwards pressure untill the water drains out. If you want more info on it go to
www.sportcompactcarweb.com and read about them. Anyway back to the CAI like HMCK20 said about the sound it's awesome before I put the BOV on mine people thought I had a BOV because you can hear every little sound the turbo makes it's great. That's my .02 cents as well.