I have for sale a Corsa Extreme Axleback for a 2013 GT for sale. I installed the mufflers around 1000 miles on my 2013. I love the sound but I really like the new GT500 axle back so I want to switch. My car has 4200 miles on it now and I have had it for 5 months. The mufflers are in terrific shape and I am willing to send pictures if you would like. I purchased these new from summit racing for $650. I am local to the Atlanta area.