Every time I come back from driving the 456 my wife says "does it have to be so loud!" I laugh to myself and say "hmm I will look into it. Maybe something is loose." I hope no one else has this problem.
Bob- I had a Novitec Supersport set of mufflers on my car. Before mounting, you could actually look completerly through them. After that set of mufflers (sold and now happily waking up everybody and everything on a 550 in CA), she loves my current set. If it gets bad enough, put on some straight pipes for a week or so just to "test" them and you will never get another complaint from her when you go back. Worked for me. Taz Terry Phillips