I recently got a single Dynomax muffler put on my V6 2003 Mustang. When I went to the muffler shop they told me that out of the Flowmaster and the Dynomax, the Dynomax would be my best choice. After the new muffler was put on I noticed that it was not much different from the stock muffler. I noticed the change in performance much not much in sound. Some people say the Flowmaster would sound better and some say it is about the same. And some say that the best thing for me to do to improve sound is to run duals. I need some professional and personal advice on what I should do. I'm not to familiar or experienced in this subject so any advice would help.