Hmmm... Difficult.
White van in background with "Automobile Club de l'Ouest" suggests Le Mans, although surroundings are a maybe bit too hilly. Car 90 doesn't tally with any entry I can find from 1966-73, mostly numbers didn't run that high for the 24-hours. Deterioration of film colour is typical of that period. Likewise hair and clothing styles. Have to say I don't know!
Stu