My friend just installed a Flowmaster Flow FX cat back exhaust on his 2009 Challenger R/T 6sp, It was $494.13 delivered, normally retails for $809, this is a new straight thru design muffler, not the traditional Flowmaster chambered muffler. This is a great affordable option. Here is a link to a video with sound clips on my You Tube channel Flowmaster Flow FX Review and Sound Clips 2009 Challenger RT - YouTube