Wilsons Sandbox

Hi List,Tweety has finally arrived in full force on my A12(9500Km).The last couple of weeks the whistle would disappear after it warmed up but now it wont go away.Previously I had considered doing the Swiss Cheese Butt plate just to improve exhaust tone but chickened out at the thought of ruining a legal spark arresting stainless steel muffler well now it's starting to look like a good option.I'd love to hear from members of the drill team with pros and cons. Did it eliminate Tweety or is it just a temporary mask?Thanks.....cosmo and tweety