Unfortunately the car is not under warranty but the opinion that I put forward to Jemca is that it is an acknowledged stock problem that the car has when it leaves the factory, therefore warranty is rather irrelevant. and they should do it anyway. They didn't agree with this and now I must phone Lexus to see what they say about it. I can replace the calipers myself for about £200, using new parts, but I don't see why I should have to do that.