i've always thought that either 1) my flywheel had heat spots, or 2) oil was leaking through rear main. i know people have followed the pedal adjustment in FAQ to fix clutch slipping, but not sure about the chatter. basically, clutch is smooth when car is cold. once stuck in stop and go traffic, forget about it. it shudders like crazy from a stop to 1st gear when driven for a while. you still think it can cure it? if so i'll give it a shot.