"We perceive external reality, the world outside the car, as "another reality," another mode of reality, not immediately continuous with the reality inside the car. The proof of this discontinuity is the uneasy feeling that overwhelms us when we suddenly roll down the windowpane and allow external reality to strike us with the proximity of its material presence. Our uneasiness consists in the sudden experience of how close reality is what the windowpane, serving as a kind of protective screen, kept at a safe distance. But when we are safely inside the car, behind the closed windows, the external objects are, so to speak, transposed into another mode. They appear to be fundamentally "unreal," as if their reality has been suspended, put in parenthesis—in short, they appear as a kind of cinematic reality projected onto the screen of the windowpane." *
The music and anecdotal storyline cause a sense of immersion and hallucination which is precisely how cinema is supposed to make you feel, but has inconsistencies which makes the viewer aware of being seduced, lured into a world that does not exist. The changing backgrounds are a reference to the old-fashioned technique of back projection that was typical for a certain era of cinema, although in this case it is created with the much more modern technique of green screen. The different times of day in the background makes the viewer aware of the temporality of the medium of film.
The title refers to the film Big Sleep (1946), one of the most famous film noir movies, while also pointing out the oneiric state of watching a film and the mediums inherent links to mortality.
*From Slavoj Zizek's "Looking Awry" (1992) p.12