My 1999 E55 occassionally has a problem on 1-2 upshift under full throttle. The car feels like it stumbles. I believe what is happening is that the engine hits the rev limiter before 2nd is fully engaged. It seems to happen more often in cold weather. The dealer has not been able to reproduce the problem. Somebody told me there is a service bulliten covering clutch pack replacement on 1999 and 2000 E55s. Can anybody help?