It's a German registration, not numpty German-look plates.
The car has been bought over here, to be built up with the ABF, now it is heading back to Germany.
You can tell if someone's bought a German car into the UK and is taking advantage - the German plates have their expiry date on them, this covers insurance and TUV. Standard plates last two years IIRC. If they're 'export' plates they're only valid 2-3 weeks. I saw someone driving around with German export plates on a camper in 2007. The plates had expired in 2005. Now that's more than taking advantage!