My '07 6 speed has done this from day one with me, which was 113k for it. I really want to know what it is. When I go to let the clutch out to go in to first gear, I get this vibrating, jiggling noise. It won't do it if I bring the RPMs up before letting out the clutch, and when i let off the gas in first or second, I get a similar noise that sounds like some connection is jiggling back and forth. Any ideas?