The silencer box is in the front wheel well on the drivers side. It will change the tone of the engine. While your in their cut off the flow restrictor on the MAF sensor also. Thats gonna have a round circle with a sensor in it and some plastic running down, with a plastic cover on the back. cut off the flat piece running down then pull off the back plate. DO NOT cut into the circle with the MAF in it, or touch it. Also cut off the end of the air box, where it goes from small to large, it will expose the end of the air filter. Then unhook the battery for 10 min (to reset the system). You should have another 5 horse or so from that. Plus it will sound mean at WOT from the front of the car. Beside buying a 80mm MAF from geno thats gonna be you cheapest upgrade right their.