[Julian Thompson]

I am in the middle of retrofitting some of these to my D3. The answer is that there is a minimum thickness (marked on each disc) and a weight (marked on each disc) as well as wear markers impregnated into each disc (little round points about the size of a penny near the edge of the disc) - you’re looking to test those three metrics to decide.

If they are worn out I have been communicating with ReDisc in Poland who will refurbish the four discs for about £6k, so it’s not too bad if you consider you got almost 300,000km of outstanding performance. Obviously if you start down the rabbit hole of comparing the market value of the car to a high ticket fix like this it sounds a bit disappointing but then I’d argue that the D3 is a car worth keeping in good shape regardless of cost. I certainly treat mine that way.