Thanks for taking a look at this post. I have a 2004 330i, 6 Speed with 144,000+ miles, original clutch. I have been noticing that when up shifting, after letting off the clutch and getting back into the gas at full throttle, the RPM's jump, then down some, and then return. Seems to happen 2-3, 3-4, 4-5, and it can be sporadic. It almost feels like I left my foot on the clutch a little or when you are driving and automatic transmission and push the accelerator to full throttle. Not sure if it is the clutch stating to slip or something else. Here are some links to a couple videos I took with my phone shifting from 3 to 4.