got a tough one for everyone. i initially thought it was the throw out bearing perhaps. i have a 2.4 5spd. and i get a buzz/ rattling sound at low rpm in first and second gear. the confunsing part is: it makes the sound even if im coasting in gear and get on the gas at low rpm ( only 1st and 2nd gear). also this sound does not show up at all when i run the car hard from a stop. so mayb its not something with the clutch/transmission???? hhmmm?? anyone?

I think if you press the clutch and hold it down and the noise goes away, it's the throw out bearing. Otherwise check exhaust, the hangers, the heat shields all rattle and make buzzing noises, especially at idle and low Rpms