Decided that I really ought to replace the exhaust while I can do it at leisure, rather than as an emergency purchase. I have been investigating source and options, and most but not all sources seem to indicate that the 2004MY system is different to the earlier one. Does anyone have any ideas what that difference might be? The Maptun one I mentioned in my original post is for 2004MY onwards, they list a separate system up to 2003MY.