I've experimented around with hoses to bring cold air in from the bumper area and I think it's pretty effective, especially for mid and upper end pull. My setup runs 2 1/2" shopvac hose up through the fenderwell and into the inner cone of a S&B powerstack filter. When you consider you can do this mod for under $25, it's well worth it. There are some older pics im my sig/link.
