Hi, I have a new A3 sportback that started making grinding metal on metal noise when reversing and setting off every morning within a week after purchase.This noise disappears later on.I took it back the dealer who kept overnight had a look and said this is normal.However I have never had this noise in any of the cars I bought in the past and certainly not in the courtesy car . It is loud enough in the morning that my family and next door neighbour can hear from inside.I said this to the dealer but he said what he has heard is normal. I am worried this could be a start of a major fault in the car. Has anyone experienced this? Can anyone advise please?