I bought a new muffler and yesterday I got the jet kit from Lancer (Super fast shipping and quality product!  Thanks, man).  Now I need an air filter to complete the project.  I'm looking at a High-Performance Foam TurboFilter on ebay and it seems like the cheapest upgrade out there.  I've also seen some cone-shaped ones, but wouldn't know where to begin to install that!  Any of you installed a foam filter?  Don't know if I'm gonna be wasting my money or not.  Price seems too good to be true.