This is common on 1 Series and 3 Series. Very common on Golfs, Tourans, Octavias, Leons, Alteas and Toledos. Starting to happen on Volvo S40s and V50s, and Mazda 3s too. All at 3 - 5 years old. The fault is with a brake pressure valve inside the TEVES Mk 60 ABS/ESP module. Volvo offers 70% but can be pushed to pay all. VAG offers varying amounts depending on the age of the car and its service record. Yes, BMW should pay at least 70% because it's a safety related fault (the ESP does not work). VOSA will not issue a vehicle safety recall, though. (S.H. later wrote back that BMW paid goodwill for the part and the labour only cost £235, which is very reasonable. Where dealers charge more than £500, that is not on because it implies that the dealer and the manufacturer are collectively making a profit on replacing a fundamentally faulty part.)