IMO, the CAI are inferior designs to the air boxes like Dinan or even stock. The factory system was designed to shorten the distance of the air flow to the turbos, a CAI increases the distance and blocks about 40% of the radiator cooling surface:
Lastly, the intake will add virtually no power by itself. You'll want to pair with a tune, and the tune itself will be what bumps the power up, not the intake.
Summary: stick to stock (remove charcoal filters or add an aftermarket drop in) or buy the Dinan box which is essentially a glorified air scoop with elements of the CAI through the snorkel.
