personally if you want a good quality filter and very safe for a CAI when it comes to water coming in. Go with AEM... get the AEM DryFlo filter, its about the same price as the K&N one, flows the same(ive had both), lets practically no water through, i had it all summer...drove in pouring rain, occasionally driving through 2-3inches of water for fun, no issues what so ever, the K&N wasnt bad with water, did let some past, it was evident when i pulled my MAF out and saw where dirt and small particles stuck to the wet spots then had dried. Also, the AEM one u dont need to oil EVER!! lol... just my two cents