When Daniel drops his assistant home at about 1:14:15 in, they park behind a 1980's VW Vanagon Westfalia.
The movie takes place in 1976, but the Disco & TV Show are constantly playing songs from 1977-1980.
The 1980 Toronto skyline includes several buildings which hadn't been built yet.
When Bastien arrives at the roof garden party, a Dodge Caravan 96 is parked on the street.
The nighttime panoramic view of 1978 New York should include the World Trade Center's twin towers.
In the New York City scene, set in 1978, the taxicab is a mid-1980s Chevrolet Caprice.
"Funkytown" by Lipps, Inc. is used in a scene set in 1976. The song was released in 1980.
"Disco Dance Party" is a French-language television show. When Jonathan hosts the program in English, there are no subtitles.