And a leading factor in that is the 70s soundtrack that infuses the world in which Detective Sam Tyler has found himself.
This week had a great example near the end of the episode. As the social worker Maria Belanger entered the bar to greet Sam, B.W. Stevenson could be heard singing "My Maria", which closed out the show. Oh mayun! I have not heard that song probably since 1973, and what a rush it brought back!
Here's a link to a youtube version of it. The video is just of the 45 record spinning on its turntable because I didn't want to ruin whatever imagery you may already have for that song in your head. (Don't you hate it when TV commercials do that? Although I do give a free pass to Nick Drake's "Pink Moon" for VW's Cabrio.)