Right its my turn to ask for help, I've just discovered that the high level brake light on my wife's Polo 9N has stopped working - low level brake lights still work okay. Any pointers before I start ripping the tailgate covers off? Ta! (thumping it made no difference!!)
As these lights are multi led - they would never all fail at once - So I would say its a broken wire rather than a faulty light.
My first place to look would be inside the rubber sleeve between the body and the tailgate to check for broken wires.