Cored the stock mufflers on my S4RS and it is a beautiful sound. Just used about 30 Dremel cutting wheels (read not really super equipped for this job) but the end job is A+. Looks absolutely stock, but sounds like a real Duck now.
I recommend this mod.
Beats the $2700 Termis. $2700 buys a lot of track days, gear and gas
Cheerio
Phil