That's it! It's the primered spoiler (hence the GRU) but the UK dealer I asked said he could only source 191 827 933 GRU (the standard primered spoiler) and not 191 827 933 B GRU (the primered spoiler with the brake light cutout) or the brake light itself, or the fittings!! it all sounds a bit silly to me, as the light itself is E coded!