My car suffers almost total power loss once up to running temperature but usually performs normally when cold. Diagnosis from a Bosch specialist says the turbo actuator has failed and that a new turbo is the answer. As several versions of turbo are fitted to this model, the only way to find out which part is needed is to remove the old turbo (the part number is inside). I am told that BMW could provide this information but that they will not unless they are doing the work. As the cost is about 1000 plus fitting plus VAT, is there a way I can reduce the the cost?