Yep mine is YD also registered at Thorne for 3 months before being owned privately:
Its a YX plate meaning BMW. They're BMW UK owned cars to begin with, registered at BMW Thorne in the Yorkshire distribution centre for BMW UK. Press cars, employee lease cars, manager cars etc.
However like mine they can only be owned by BMW for 3 months and then have to be sold on. They usually come with high spec and were usually reduced well following their initial sale.
My car was sold AUC after BMW owned it and then sold AUC again after that owner sold it. It wouldnt bother me if it was an employees car but I've read that press cars can have it a little hard to begin with in life..