Hi, My e60 530d sport has become hard to start in the morning. Takes 10/15 seconds to start.Once started the car goes fine. But when stopped, it takes 2/3 sec on turning to start again. I have been told 3 of my injectors have problems. The garage says i need to replace all 6!!!! Is this true???? I would have thought replacing the 3 bad ones would be enough.Does anyone no if this is the case. Do i really need all 6???