Ironically, John Jarratt doesn't like to watch horror movies and stated that watching Psycho (1960) frightened him when he was a child.
Loosely based on the Australian serial killer Ivan Milat, who was serving a life sentence in Australian jail until his death on October 27th 2019.
(at around 36 mins) When Paul is speaking to his girlfriend, the connection begins to get bad which forces him to hang up, right before he hangs up you can hear Mick's laugh.
Both the gore f/x and vehicle stunts were done practically.
Supposedly, there was a back-story on Mick Taylor written in the original script that was supposed to be shown in this film; it revealed more details about Taylor's past explaining what made him become such a sadistic, violent serial killer. Obviously, the idea was scrapped and nothing about it was ever filmed. Later developments showed this information on Mick Taylor's history would finally be revealed in the series, Wolf Creek (2016).