mines 2003 his is 2004 both with standard exhausts.  I guess not many people have noticed the difference, even when you go to meets with others you generally don't listen to each others standard exhausts.  There is definitely a difference so I wondered what it was on my car that made it so quiet?  Not sure i could be bothered changing it for a UK standard one but its definitely an idea.  How much does it cost to fit one?