Forget the intake, you'll get no performance gain. Actually, you might be worse-off with an aftermarket CAI b/c most of the ones I've seen for the B5 aren't really drawing the air from the outside. The stock intake, which actually is a CAI, will be your best bet. Stick with it. :wink:
Now, if you're looking for a louder intake sound with no performance gain, then go with an aftermarket CAI. :roll: