The position of Ms. Bentley's racket while she's playing tennis.
When Miss Bentley is listening to the BBC broadcast it reports a meeting between "M.P. [Member of Parliament] Winston Churchill" and German foreign minister Ribbentrop over German demands that, if not granted, would lead to war. The movie takes place in April 1939, and Churchill was not prime minister until May 10, 1940, and not yet a member of Prime Minister Neville Chamberlain's cabinet until September 3, 1939. While Churchill was still an influential member of the Tory party, it would have been unusual for the German Foreign Minister to confer with him and not Lord Halifax, who was Britain's Foreign Secretary at the time.
At 15:23 the Major clearly hits the ball over the net and onto Miss Bentley's side of the court but at 15:27; Vittorio sees the ball go up and over the roof of the pavilion [where the onlookers are seated underneath]. Then at 15:31-36, the same ball hit at 15:23 can be seen again as it rolls across the court from Miss Bentley's side and past her and the Major's unsuspecting feet rolling to a stop just outside the pavilion. Next Miss Bentley calls out to the onlookers for a ball but she would only have to look to her left and find the ball on the ground.
All the cars have right steering wheel, since it is Italy they should be left.