Came across this yesterday, on the back roads of Oxfordshire! Quick check to Google to make sure it wasn't Autocar kerr-ching fodder - it has been released already - but press car or uber stealth test car?? And why doesn't it have the upper sticker on the no plate? Tax dodger or nil TUV requirement when new?? Red plate on the RHS looks odd also - German trade plate import, owner-collected maybe? I couldn't see which side the steering wheel was on...
Also, the "tax" thing you're referring to is for emissions and MOT. If memory serves the front one is MOT (circle) and the rear one is Emissions (hexagon)... I think. That number plate is an export plate. In other words, it was purchased in the Fatherland and given a registration specifically for exportation purposes. So it won't need an emissions doofer as the final registration country laws will apply. The date is the date by which the car must have been exported from Germany.