I'm new to the forum, but I've combed through the exhaust threads and did not find a specific answer to my question. It appears that there are no longer any catback exhaust systems available for the GTPs. I have an 06 sedan with the 3.9 V6 and stock dual tail pipes. My question is: What is a good drop-in replacement for the stock muffler (Flowmaster, Magnaflow, etc.) that will enable me to keep my stock pipes and tips. I had a really good experience replacing the muffler on my 06 Colorado pickup (I5) with a Flowmaster and am looking for the something similar for my G6. Does anyone know what specific mufflers will fit in the best? Looking for part numbers or links...