[haze 11]

i have a 2021 m235i gc UK spec and recently after a bit of a drive somewhere if i then reverse into say my drive way or a parking space there will be like a mooing noise and vibration from the front brakes, now i had booked the car into the local bmw dealer to check this over and they came back with the conclusion nothing was wrong as they couldnt identify the noise whilst it was with them as the noise wouldnt appear, any way long story short there was something to do with an engine mount need replacing so they did that and i had the car back yesterday and i had just been out in the car to get some lunch and what happens when i reversed the noise appears. someone please help me understand why this is happening.