I think Demon's got the right idea.
Alternately, I have the MSDS and the Brullen "quiet" with a resonator...and yup, it's quiet. It's still very sporty sounding, though. PM me with an email addy and I'll email you a short sound clip.

Derek Scion xB 5-spd Previous: 2000 Silver Frost SVT Please share the road with cyclists.