3.6 Pentastars are easy to Drone and majority with exhaust mods sounds like an Import Ricer / Angry Bee at higher RPM's. There is not much in the way of improving one IMHO for the cost involved for the difference. Also a J-Pipe helps reduce the Drone a bunch but it defeats much of an Aggressive Exhaust sound. The Reason this is so difficult of an Engine to get a Great Exhaust sound is because of the Head / Header Exhaust Port it compresses in the head to the Down Pipe from 3 cyls. This creates the Higher Pitch the Engine Makes when trying to modify the Exhaust.
This is the Areas that Create the High Pitch Notice they are very shallow passages for the Exhaust to come out and still within the Head The 1st Cyl on each head Has a very restrictive passage almost a 90 degree bend right out of the Cylinder the Back one about a 89 degree Angle. That said when you reduce the Muffler and Resonator it no longer filters the Exhaust Gasses making them louder / amplifies your Exhaust Tone with the Pentastar its a very High Pitch Ringing Drone. Also this is why the mods do not help with MPG or HP on top of sounding like angry Bees.
Ive listened to Hundreds of Videos and visited many Exhaust Shops and Heard in Person Several Cars getting mods done and why I never bothered to
modify my exhaust. While some are happy with the results which is cool perhaps mostly the Placebo Effect the Cost and result is not worth it again IMHO.
If you want to reduce the Drone get J Pipes installed.