I have a noise very similar to clutch rattle. My noise only appeared after the 1-2 grind fix. It appears to only happen for even gears (2,4, and I imagine 6th - 4-5K in 6th is a little too fast to test though) and is most noticeable in 4th gear between 4 and 6K on deceleration. It mostly parallels the clutch resonance problem others have describe... Except during acceleration through 4-5K rpm in 4th I get a whistle. Almost bad differential noise like, but sounds for all the world like it is coming from the shift knob/front of engine area.

I have been trying to get it fixed for 13 days, see http://www.s2000online.com/forums/showthre...64993#post64993 for more details.