Evening all!
Finally put my calipers back together tonight after a little renovation (you might be able to spot what I did in the picture...). One spring went on easy, the other was a pig but both on and seemed settled.
Took her out for a spin
and I hear a tinkling noise (was only going slow)...pulled over being very gentle on the brakes to find this!

I knew it went on too easy!
How hard are these to get hold of? Will any BMW dealer have them in stock? How vital is it? Am I a complete twit?
I think I probably already know the answer to the last one......
Finally put my calipers back together tonight after a little renovation (you might be able to spot what I did in the picture...). One spring went on easy, the other was a pig but both on and seemed settled.
Took her out for a spin
and I hear a tinkling noise (was only going slow)...pulled over being very gentle on the brakes to find this! 
I knew it went on too easy!
How hard are these to get hold of? Will any BMW dealer have them in stock? How vital is it? Am I a complete twit?
I think I probably already know the answer to the last one......