Easy test: keep all safety nannies on and check if the yellow DSC light quickly flashes when this phenomenon occurs.
If the DSC light does not flash, it's likely that the clutch starts to slip.
I remember a Belgian guy testing one of the first 1M loaners last year. He reported that the clutch was already slipping despite the car having clocked only a few K kms. Test drive = putting to the test what the car is capable of. Decent car journalists do not perform wild stuff with a loaner (cold engine, brakes, shifting, etc.), so the story goes.
Small question: did you install a so-called
"clutch stop" in your 1M (small device allowing you not to push the clutch to maximum position: see
http://www.1addicts.com/forums/showthread.php?t=602966 -
http://www.clutchstopper.com/index.html -
http://www.ebay.com/itm/ws/eBayISAPI...E:L:OC:US:1123) ?
If you got a clutch stop, or you have the driving habit not to push the clutch till its maximum position, and the clutch has to be replaced, then that might be the cause.