Sorry for delay.
To clarify this displays on the mfd between speedo and Rev counter.
The symbol is the same one as when you press and hold the button to turn ESP off and put it into sport mode (was playing around at the w/e whilst sat in a car park waiting for my wife and daughter). It showsa smaller version of the symbol, in white, of the vehicle with two semi circles at the same positions mentioned above and says something like ACC and front assist deactivated or unavailable (wife has got the car at the mo so can't be specific)
So looks like a prob with the radar function? Next time it flashes up car will go into the dealers for checking and software upgrade.
Cheers