Hey is this a bolt-in mod? If so how much does the bolt-in cost that would remove the rear cats and have the X crossover? This looks like a cool HP or 2 mod. Oh, Most important, what does it sound like? I don't want anything obnoxiously loud! The tune/intake mods throatier sound is much cool and I don't want to change it that much! Any help you can provide in these points would be (in my case at least) greatly appreciated!