I have the Super 40.
Not common, in fact new muffler set out and has better performance and with my o/r x pipe, louder and better sound than most stangs out there.
See it here.
http://www.flowmastermufflers.com/cg...er/952448.html
just get the 2.5 size at least.
I will have sound clips up soon. Many people say that i am a crock load of crap when i say that they are good. Most have not even seen these on cars yet.