i bought the rear end for my exhaust and just brought it to an exhaust shop. (which is why it looks the way it does, im getting it fixed soon) 2.5 inch from the cat back. it was ****in loud. so i had them put in a 4 x 17 inch high flow resonator, and damn does it sound good. so far my exhaust has cost me a lot. but thats cause i keep changing it and making it better. i like mine more than the factory Apexi N1 catback exhaust