MTM make exhausts that have a valve system inside them that allows you to choose when and how loud you'd like your soundtrack. There are other systems that have the valves inside them but they are are set to open at something like 4,000 rpms which is fair enough. I'd say we'll begin to see a lot more of these types of exhausts on the market next year but for the moment the baffles works well so I dont see any reason to worry about this new legislation.
Also, bearing in mind that Ireland is constantly being fines for breaches of European Water Pollution Directives it seems very unlikely they will be any more effective in policing a Noise Pollution Act (whenever they actually get around to introducing one).
Frawls