I have that to, as do a few other members on the board. It has something to do with how they attached one of the heat shields on these cars, where they can start to come loose and rattle until they warm up a little bit. For me it seems like it is only the first couple times I depress the clutch pedal after starting her up up if she has been sitting around for a 5 or mor hours.
There is more information on this forum, I just don't remember where or the really specific aspects of the problem.