Simon,
A point I should have added in my previous post.
As part of a general brake upgrade on my '4' I not only fitted EBC greenstuff pads but also went for the EBC ventilated discs- primarily to prevent gassing and the build up of high spots.
At the time, Ben Duncan and I had a conversation in which he said that of late he wasn't very pleased with the discs because they were rusting quite badly but we went ahead anyway.
He was right- they were a bit of a disaster. I don't want to be too general on this because it might be that we caught a 'bad batch' and my experience of other EBC stuff has been and is excellent- to the extent that we run greenstuff on all our cars now( not least because there's less brake dust to clean off!)
We've now taken the EBCs off and gone with some AP Racing discs which seem ok so far.
