Well went to local muffler shop. Did the one ball mod. And although I didn't get onto a major highway, I must say aside from accel/decel, there really isn't much of a difference in sound. not sure whats next. Oh I have a 2006 S.

 

Yea, one ball is not a major difference but some. I noticed the change on my 04 right away, both inside and outside the cabin.
Performance was a nothing for me, that I could tell.
Still one of the best cheep mods.