[ze_shark]

Go back to the 355 OEM muffler then ...
Still have not figured out why people would want something else. the 355 sounds gorgeous with the stock exhaust, and not outrageous or overly loud, even with the vacuum valve stuck open.
Maybe you'll find a brave soul who wants to swap ?

 

[ze_shark]

Yes, there is a vacuum actuated valve on the OEM muffler (like the 550 and the 360 as well I believe), which you can also stick open if you want a slighty meatier note at low revs.
Car sounds gorgeous that way, especially if you have a spider or GTS.