Have a 2013-2014 GT500 Quad Exhaust Rear Diffuser. Yes, this requires you to trim your rear bumper cover to fit it. Very simple install. It is used, but in good condition. Believe Tasca sells these for around $200 shipped? Correct me if I'm wrong. Will sell for $120 + shipping costs, which I get very good deals on. Will trade straight across for a Boss 302/Cali Special Rear Diffuser Located in Dickson, TN.