Most of the gabbers in the movie are real gabbers. All of them are listed in the end credits.
For some scenes they have recreated the famous Energiehal which was demolished in 1999 using the oirignal blueprints and with the help of famous hardcore DJ George Ruseler, also known as DJ Distortion, one of the members of the famous gabber act Rotterdam Terror Corps.
The movie mostly takes place in the city of Rotterdam in the year 1996 when the hardcore scene was bigger than ever. Rotterdam is the city where hardcore music originated.
One of the bodyguards of the drugsdealer from Brabant is called Piet in the movie. This name was completely improvised by actor Huub Smit. They shot this scene multiple times and everytime he just made up a random name. Eventually in the scene that was used his name was Piet.
The big rave in Germany at the end of the movie is actually shot in Schiedam, a place close to Rotterdam in the Netherlands.