The music vehicle has the steering wheel on the right, all vehicles in mainland Europe have the wheel on the left.
When the air-raid siren sounds and the cast come out into the courtyard of the chateau via the flagstoned porch, the sound is that of feet clomping on a wooden set.
When the landing craft is seen coming to collect them from the beach, there is a shadow of another landing craft in the lower left corner of the screen.
When Garnett puts on his glasses in the car, studio lights can be seen reflected in them.