Check out my muffler. Is this outer sheet metal wrap with the very lumber banding looking straps stock?? If its not that sure would explain the slight leak... I hope its not stock thats a pretty piss poor design if it is.
(sorry I could not get my images to load right so you will have to cut and paste)
http://imageshack.us/g/217/img1123sl.jpg/
(sorry I could not get my images to load right so you will have to cut and paste)
http://imageshack.us/g/217/img1123sl.jpg/