Charlie tells Reese that his one vice is a Royale with cheese. In the movie Pulp Fiction, John Travolta tells Samuel L. Jackson that in France, a Quarter Pounder is called a Royale with cheese.
This is a spy genre film and it is interesting to note that the title of the earlier film Deux Anglais à Paris (1955) is said to have been the inspiration for James Bond creator Ian Fleming for the title of his 1957 James Bond spy novel, "From Russia With Love" which was later made into the film Bons Baisers de Russie (1963).
The car chase was filmed on a new motorway outside of the town of Annecy which had yet to be opened to the public. Eagle-eyed viewers might be able to guess this as, in most of the shots, there is no traffic traveling in the opposite direction.
The fact of not having traffic on that direction was previously justified as having the highway locked for the arrival of the diplomatic convoy.
When Caroline enters James' apartment you can clearly see the book 'Nikita' which was written and directed by Luc Besson, who wrote "From Paris with Love".
Both this film and Bons Baisers de Russie (1963) feature a scene where an agent must finish a game of chess after being summoned by their handlers.
Kelly Preston: As Reese calls his girlfriend from the Eiffel Tower cafe, Kelly Preston can seen sitting behind him. She is wearing sunglasses and seated at a table with two children.
Luc Besson: He can be clearly seen getting out of a car and facing the camera as it moves up a line of parked cars.