Hi,
My father and I have a white E89. When we bought the car the dealer said they were not able to fix the noise the roof makes. It is squicking and especialy when we went over a bump.
I am an industrial designer and i found out that 1 part in particular was the cause of this noise. In the centre of roof beneath the back window there is a part that go's into the car. THis part is made of metal and inserts into a plastic part.
The plastic part is coated with a rubber kind of layer. i found out that this part was worn. Instead of buying a new one i decided to make a 3d printed part made of complete rubber, so it could wear down.
For our car it completely resolved al noise and we can enjoy a drive with the top on up and down!
You can take a look if it cuases you problem. I can share the CAD model so you can 3d print it yourself.
kind regards
