Well took the wagon to my man and he has reset the fault which was:
Fault Code = P00AF
Description = Turbocharger/Supercharger Boost Control "A" Module Performance
Anyhoo, according to another person or two, I need to drive it hard from time to time. E.g. 2500 - 3000 rpm
Funnily, since owning this car in October 2014, I have always driven it carefully, slowly without harsh acceleration.
This last weekend I thrashed her for the first time and the light came on!. D'oh!
The moral of the story is what? Drive it like you stole it or carefully?