"Mado" takes place in some kind of ultra-sophisticated world, where the young on welfare move in easy sociability with the middle-aged rich. Oh, the young may grouse a bit because the rich own the things they use, and the older people look sad when the young prefer one another sexually, but generally they have finally learned to share.
In this Never-Never Land (or Jamais-Jamais Pays, as James Thurber would say, this being a French film), the queen is a young toughie with a fantasy-prostitute career. Her carefully selected clients adore her - one who touched her heart by giving her a tank watch is afraid to propose because she might reject him; another seems inordinately proud of showing her off socially - and when her contemporaries mildly criticize her occupation, she silences them with the enormous philosophy, "People sell themselves in different ways."
Mado is, in fact, the mistree of, among other things, the swift psychological putdown. She dumbfounds a patron who has take on her whole gang of friends with the observation, "You want everybody's love, but you can't love anyone except yourself." Ottavia Piccolo and Michel Piccoli (coincidence of names - this is not a small cast) do a lot of deep staring in these two roles.
But in case you still don't get it, the last part of the film runs through it all again in symbolism: A motor caravan, stuck in freeway traffic, turns off onto an unknown byway in the rain, and gets splattered with mud and stuck; but later, it is discovered that those who stayed on the main road were killed.
Life, as we say, is like a journe . . .