Graeme, thanks for birthday wishes
What you describe meets exactly my experiences. When driving slow there is no issue. But when braking down from ca. 100 km/h or more I have the same strong shudder, most of it around 90 or 80 km/h. The (young) mileage of your car is also comparable to the intervals of the need to change my discs. It is very helpful to know that also cars with wider tyres like yours could be affected. Therefore my idea to swap to 185/70/15 is probably not the first solution. Perhaps it could be a heal to look at different discs which will be of same size etc. As I said I never had this issue with my Roadsters or my former P4SS, each of them driven more than 22.000 km.
