I too have this rattle at high revs, it seems to be when the rev limiter cuts in,or possibly when the clutch is depressed ,the rattle lasts about 3 seconds, it starts fast then tails off,or slows ,as if it's looking it's inertia,all within about 3 seconds. I also have an occasional rattle from the steering module,that sounds very similar, only on particularly cold mornings,or if the car has stood for a long spell ,e.g. 7 days. My car has had a new steering module under warranty,when it was about 4 years old,by the previous owner. Could these two rattles,be the same thing ? I am monitoring this situation. It is a shame because I own a megane 250 cup ,as well ,and I love my twingo just as much,it is the best looking small car on the road ,bar none ,and is last of the old school hatches , like my mk1 golf gti, from the 80s. A future classic, normally aspirated ,drivers car.