I have a brand new magnaflow competition axel back exhaust (part #15594) I am looking to sell. This fits the 2011 through 2013 Mustang GT (I believe it will also fit the shelby). I only opened the box to look the parts over. I am located in Austin Texas and would like to deal locally but I could ship if needed (buyer pays shipping). I bought to put on my '13 but I am deciding to go another route. Please let me know if you have any questions. I paid $450 but willing to part on an OBO basis. I just want it gone. Thanks for looking.