return to the brake light issue, new lamp holder did nothing .. hmm
took apart and looked, found metal edging burnt or worn away (the curse of the automatic I suppose)
a blob of weld and a bit of linishing later we have some metal back in the right place
I don't know what metal that is or what coating they put on it but it gave off some funny smells and yellow muck
anyway with that all wirebrushed clean, the lamp back in and a psu connected to the metal strips it now lights up. refitted and no more message, happy days