I replaced the trim and clips (I'm in the US) and ordered them from BMAparts.com but hold onto your shorts, they are $100 each. The middle cup piece is $9 and the clamps that go onto the windshield are $2.25 each (there are 14 of those, I believe.)
The install was documented in a thread on this forum and it has 5000 miles on it, so they've not failed (touch wood.)
Here's the thread...
http://www.bimmer.info/forum/showthread.php?t=28111