Conversation so far:
what year was Gigi released?
In March 1957, the duo began working in Paris.
who developed the main character?
so Lerner agreed to write the screenplay only.
He and Freed discussed casting.
how did they pick the cast?
He and Freed discussed casting; Lerner favored Audrey Hepburn, who had starred in the Broadway production written by Loos.
how did they choose the location?
He decided to approach Loewe once again, and when he suggested they compose the score in Paris, Loewe agreed.
how did they come up with the score development?
Lerner proposed Dirk Bogarde for Gaston.
Lerner agreed to write the lyrics.
where did they film most of the movie?
the duo began working in Paris.
did the actors all get along?
When he discussed his waning interest in wine and women in favor of performing for an audience in cabarets.

Question: are there any other interesting facts?
Self-contained rewrite: Are there any other interesting aspects about the film Gigi other than being filmed in Paris?