I have an AEM CAI on my 6th Gen. It produces a nice sound and I'd say around 4 hp. Also, gas mileage improves a good ammt. The CAI isn't going to f#$k you up unless you try to drive through a river. Normal rain/snow/big puddles aren't going to hurt you. Standing water=bad. But yeah go for a quality intake and filter. Even though aem anfd K&N filters don't need to be replaced, they do need to be claened and oiled every so often. I've been running my CAI for 3+ years now with 0 problems.

Eh, $28 bucks for an intake...i don't know I paid well over $150 for mine...remember, more often then not you get what you pay for.