so my friend has a bad *** dodge like mine, with duals. i always wondered how he got his so loud so I looked under his rig and there is no muffler. and it sounds pretty damn awesome if you ask me. well anywho, went to the muffler shop and they said its better to do a 'cheater' muffler, this thing is like 8inches long, single in dual out. any idea about these? he said the would sound loud and low and 'mix's' it at the same time.

 

sounds like you need to go to the shop that did your friends muffler. That shop is trying to sell you another part you dont want.