In a Dutch Playboy interview conducted at the time of this film's release, Wim Verstappen explains that the original plan was to follow up Grijpstra & De Gier (1979) with an adaptation of Janwillem van de Wetering's 1979 novel 'The Maine Massacre'. But when plans for that installment fell through, Verstappen went to help out Guido Pieters on Ciske the Rat (1984). The director claimed the writer never forgave him for that, and when Van de Wetering went to stay in Friesland, he took Verstappen's typewriter with him and wrote 'De Ratelrat' . According to Verstappen, the entire book is filled with spiteful stabs against himself (with him being the rat of the title).
This film features 7 Playmates from the Dutch edition of Playboy. They are: Daphne Bolt (March 1984, as Daphne Walters); Lilian van Everdingen (October 1984); Saskia Van Rijswijk (August 1985); Linda Dubbeldeman (October 1985); Miriam Stemmerich (April 1986, as 'Marjorie Christie'); Lesley Lengkeek (July 1986) and Fientje Hoogstad (March 1987). All of them were featured in a special concerning 'De Ratelrat' in February 1987. This issue also included an extensive Playboy interview with director Wim Verstappen and a positive review of the film, with a still of leads Peter Faber & Annemieke Verdoorn in the nude.
In the final scene that leads to the end credits, Grijpstra & De Gier are making music (playing the drums and flute respectively) in their office. A police officer played by Saskia Van Rijswijk is seen listening at the door, but she retreats when the commissioner played by Bernard Droog catches her in the act and begins to listen at the door himself. Originally, the scene was a bit longer: Saskia walked in on another police officer, this one played by Daphne Bolt who was listening at the door before she herself began doing the same thing. Apparently the editor decided that three people caught in the same act was one too many.