I purchased and installed a cat-back Gibson system (GIB17402) for my 2007 Commander (3.7) and after driving for a while today I have to say I am disappointed with it. It might be that I am so use to having a deep tone from my past V8 vehicles but with the new system the Commander now sounds like, for a lack of better words, a "rice burner". The Gibson website says that it fits the 3.7 and 4.7 but I am thinking that the system is, and should be, only for the 4.7 because it is a V8. Every time it revs up and shifts gears it reminds me of a wind up car. I am seriously thinking of going back and having the factory piping and "hot water heater" muffler installed again. If anyone else has this system, please leave a comment on what you think of it and its' the sound.