I researched this fully last year. I installed several mufflers on my 2006 6 speed...including the Flowmaster Super 40 and the 40. I ended up going with STRAIGHT PIPE, which is PERFECT. No one could have convinced me to do this until I spent $$$$ trying different mufflers trying to get that "sound". I thought it would be tooooooooooo loud, but it's NOT AT ALL. Automatics are probably a different story, since they cruise at a higher RPM....but straight pipe is quiet and rumbly at idle, quiet at 70, but like a cannon shot when you slam it. I'd like to compare it side by side to Mike's system on a 6 speed. I bet they sound close...
Here's a link to the thread about my muffler research:
Got My Flowmaster Super 40 Installed Today...Surprised
Hope this helps!
Jeff
