Back to the thread: I replaced the OEM tube with the no-noisemaker equipped Lincoln part outlet tube, p/n AA5Z-6F073-C. I can't say that I've noticed any significant difference (not having any sound-level devices installed) but I will say from recent (today!) experience, with the windows open, I can't tell whether the front end or back end is making more (pleasing!) noise. With the SCT tune, it's quiet and tame until about 1800-2000, then there's a "kick-in-the-butt" as the torque kicks in and suddenly you're crossing MPHs more than planned (at least while I was working on breaking in new brake pads!) I still haven't punched full throttle from stand-still through any range, but the kick(in the butt) I felt today shows me the 2011 (with CAE, plugs, and SCT tune) still has lots of room to give my Mustang a run. Good thing I can't be in both cars at the same time!