I made my FWI for the cost of a low profile Spectre cone filter, plus a coupler, a roof baffle, and some PVC which I painted black, and can be found at home Depot. Took about an 1:30 to install because I'm a perfectionist. Has a nice roar at WOT and gave me a bit more throttle response/mpg.

Just take off your wheel well/splash guard and seal it up before you do it, it barely gets water in it stock. I live in PA, I understand deep puddles :P