So, I've been considering taking 20-30 minutes out of my busy life to get a K&N High Flow Filter, and do the Swiss Cheese Mod. The only questions I have are: Does this mod affect the gas mileage? Is there a possible way to replace the AirBox itself? If so, how much would it cost? Thanks

So i was contemplating doing the swiss cheese airbox mod where you take a drill bit and drill a bunch of good sized holes into the bottom of your airbox, and i just wanted to ask the Jetta community before doing something potentially stupid. Thanks to all who respond to this message.