I have a 2006 530 6sp that has a strange squeak like a brake squeal when reversing. It only happens sporadicaly. I took the car to the dealer and as typical, they could not reproduce the problem and said they couldn't find any problem.

Has anyone had experienced this same thing?

Thanks for any help.

 

Yes, my 525d does this too. No idea why, and I don't do enough reversing to be too bothered by it

 

You can try scuffing up the rotors and lightly sanding the pads, to see if the squeeks will go away.

 

I have the same thing on a 2004 545i, 6-speed. I think it is the sensor that measures your brake wear. Originally the dealer would address it during services, then they stopped. They maintain it is nothing to worry about.