A Dozen Phantoms

Popped to another town ( no names) on a shopping trip, and came across these 12 silver Rolls Royce Phantoms parked up, with very smart chauffeurs polishing and tidying the cars, each of which were displaying a Union Jack and an Irish tricolour.
Each car also had unique registration plates, all number 1 with two or three letters.
No idea what was going on though!