Thread necro:
I am curious to know the mileage on the car when the turbo work became necessary? Stock ECU or flashed software?
I am considering to buy a Z4 35is with the 250kW version of the N54, achieved by overboosting between 1500 - 4500 rpm under full throttle. It would be interesting to see if wastegate rattles and turbo failures occur earlier on the 35is version than on the regular 35i because of this overboosting capability.