James Gandolfini and Edie Falco were supposed to do a cameo as their "The Sopranos" characters in the final episode of season 2, with Frank Tagliano stumbling across them in a random cabin. Van Zandt was in talks with director David Chase to direct the scene, but plans ended with Gandolfini's sudden death in 2013.
Throughout season one Johnny quotes Casablanca several times. One of the more popular ones is when he gives Jan a job in the last episode of the season and says "this may be the beginning of a beautiful friendship." Then shortly after he asks the piano player to play that song he likes.
The trivia items below may give away important plot points.
References The Sopranos early in Season 3 when Frank is shot, and moved into a room in the Hospital with a crazy old man. Frank hopes it's all a dream, the old man replies saying it is a dream and calls him Silvio, the character Steve played in The Sopranos.
The series was cancelled after third season due to a conflict between "NRK" (Norwegian TV channel broadcasting the show in Norway) and Netflix, where NRK published the third season on its website earlier than Netflix. This led to some contention due to the viewers having the possibility of watching the whole third season on NRK's website for free before Netflix uploaded the season.
In the very last episode, "Loose Ends", Bruce Springsteen appears together with Steven Van Zandt as Giuseppe 'Joey the Undertaker' Tagliano. The episode has its title from the Bruce Springsteen song of the same name. The two play together in The E Street Band.
Season 2, Ep 8 Reference to The Sopranos. When Frankie is talking to his ex Angie about coming home she says "This is like a Sopranos episode", it then cuts to him and his crew from Lillehammer driving into New York. The Sopranos theme is playing on the car radio reminiscent of the opening sequence.