Window Badge

Presumably monogrammed just on the near-side because only pedestrians would read it when parked

Hiding under the Petrol Filler Flap is also the LPG filler nozzle. You have to use an adapter which is a bit fiddly (and can be downright annoying at some pumps) but there's no separate LPG filler cap spoiling the aesthetics and the fuel costs are much the same as a small modern car.