Cold air intakes are a bit of a debatable topic. Will you gain horsepower? Maybe. Will you gain horsepower when you install both a CAI and an exhaust system? I'd say, probably. I'm confident I did. Regardless of the power gains (or lack of), one thing will most certainly change about your car... the way it sounds.

A CAI will transform the sound of your car. When the turbo spools up, theres a definite sucking noise, much louder than stock. This is great and all, but has nothing on the diverter valve noise that the CAI lets you hear. Stock, there is no DV noise, with the intake it sounds a lot like a blow-off valve. You really have to hear it to believe it.

Some people will like the noise, some people won't, thats really your choice. It certainly make the car sound sportier. I got a good deal on my intake, so I figured it was worth a try.

The intake I got was from the folks at www.20vt.com. Some say their business ethics leave something to be desired, but I got a good intake at a good price through them. Your mileage may vary. As far as CAI's are concerned, they all pretty much function the same. Just get the one that suits the price range you're looking for. It's my opinion that there is no reason to pay over $150 for an intake.

Installation can be a bit tricky for the unexperienced, but isn't anything the novice can't do in a couple hours. Here are some links that might help you out:

EuroSport CAI Installation (with pictures)

20VT Intake Installation Instructions (without pictures)