on my way back from Croatia last week as soon as I went over 85mph getting a low frequency rumbling noise all over car . no vibration almost like a harmonic but it doesnyt go away up to 110mph. Suggestions are rubber doughnuts on propshaft rear half shafts. also but completely separate gearbox sometime holds onto 1st gear up to 5000rpm and then clunks into 2 and 3rd almost instantly. Oilchanged and new valve body fitted three months ago. Dont think the two are connected though any ideas?

 

If you've never serviced your driveline guibo, I'd check it out. Google BMW drive line noise to see what your driveline noise matches as our driveline shares most of the parts with BMW.