While we were deciding what to do about it, I drove past a local garage with a Trophy Blue ZS on the forecourt. I was in like a robber's dog. After some negotiation the ZR was accepted in part ex (all faults declared) and the deal was done. It cost me about the same to change cars as it would have done to get the work done to the ZR so that was a win in my book
The ZS is a lot nicer car with non of the scabbiness that the ZR has round the wheel arches.