Each season uses a different recording of the song 'Way Down in the Hole' over the opening credits. For this season, it's provided by Tom Waits who had originally written the song for his 1987 album "Frank's Wild Years".
Frankie Faison and Andre Royo both have reduced roles in this season though they still keep their main billing in the opening credits, but only in the episodes in which they appear (they do not appear in the season opener).
The focus of this second season is the decline of the American working class.
Officer Beatrice 'Beadie' Russell examines a cargo container with broken seals. She has to climb over PC cartons labeled "Gebarowicz Tecnologia". Halina Gebarowicz is the art director for "The Wire".
Chris Ashworth went into his audition for Sergei with a Russian accent. The production was surprised to later learn that he actually comes from Virginia. At that point, Ashworth had never taken an acting or dialect class.