This kit won't fit on the 2013 or 2014 Mustang V6s without trimming the rear valance due to design changes Ford made. This kit will only bolt on to 2011 to 2012 cars out of the box, and Magnaflow does not have an equivalent kit for the 2013 or 2014 Mustangs, unfortunately. It's extraordinary rare for Magnaflow to mess something up.