Neither this sequel Sweeney 2 (1978) cinema movie nor its prequel Sweeney! (1977) theatrical film had a title that conformed with its source TV series title, The Sweeney (1975), dropping the word "The" in both cases. It would not be until the remake movie The Sweeney (2012) was made that this would occur.
Actor John Thaw once said of this movie for the film's publicity: "The Sweeney really is your urban western. But the team - the cameramen and the director - are almost semi-documentary in style and therefore you get much more sense of reality than you would in a studio set-up. And we never work in a studio".
The name of the police unit was "The Flying Squad". This is in real life an actual police division. Wikipedia explain it as being "a branch of the Specialist Crime & Operations section, within London's Metropolitan Police Service. The Squad's purpose is to investigate commercial armed robberies, along with the prevention and investigation of other serious armed crime. Possibly one of the best known operations of the squad was their foiling of the Millennium Dome raid".
Dennis Waterman once commented on the violence in the Sweeney shows whilst doing publicity for this film by saying: "It's certainly no more violent than the real Flying Squad. The stories that we hear from policemen that we know are terrifying. We don't introduce gratuitous violence, but it is, in real life, a violent job, and to pretend otherwise would be ridiculous".
The movie's signature stunt, the driving of a car through a shop-front window, or a "death defying car leap" as the publicity exclaimed, was filmed in one take with three cameras. The window was on a mezzanine floor, about ten feet (three metres) above the ground.
Both this sequel and its precursor cinema movie Sweeney! (1977), spin-offs from its source TV cop series The Sweeney (1975), were both made and released whilst this TV show series was still being broadcast on television.