Thanks - My nerves are starting to get the better of me now though...
As for the rolling road bit - do they do the brake testing on that? Only when I took it for the MOT, the inspector there asked me what sort of diff I had, and when I said it was an LSD, he said 'good job I didn't put it on the rollers then' and checked the brakes with a weighted gadget he put on the passenger side floor during a quick drive up and down the test centre service road.