So I'm looking at cold air intakes for my car and I notice there's a few different ways they have them set up. One way, it replaces the stock intake and sits right where that is. The other is going down and right behind the front bumper. Which way will give it the best performance? I notice the kind that goes behind the bumper is a little more expensive, and I'm assuming that's because of the power it produces. But I'm not sure, so help appreciated! Thanks guys.