i have the same flywheel installed as of last May and I got chatter aswell. I actually just blew up my clutch about 3 weeks ago and I'm pretty sure it had something to do w/ less vibration damping b/c of the now single mass flywheel as opposed to the stock dual mass. I did some research into upgrades and basically that the trick of the trade w/ our e30 M42's is to get the lightweight flywheel and then pair it w/ a complete stock clutch kit from a '95-'96 M3 w/ S50 motor (not S52). Apparently the clutch is supposed to be a perfect fit and has built in vibration dampeners on the clutch disc like other discs paired w/ single mass flywheels and will def yield much more clamping force and can withstand the newly freed power from the lighter flywheel a lot better than the stock M42 clutch. By the way my clutch was only 14 months old when it completely disintegrated. My mechanic said that he had never seen anything like it but everything was ok except for the clutch disc. I ordered the M3 S50 clutch from
http://www.theeurodepot.com for $225 and BavarianAuto (who told me about the trick setup) tried to sell it to me for $418. I'll let you know how it works out when I get my car back w/ the new clutch