The film had already received notoriety in the UK after being featured on the BBC News as part of a report concerning the availability of uncertified video films. Even though the film had received a cinema certificate by the BBFC this led to it being banned and included on the DPP list of 72 video nasties. The film was eventually passed uncut in the UK in 2005.
The trailer for the film was featured on the 1984 CBS/Fox video VHS of The Rocky Horror Picture Show (1975) in Australia and New Zealand. Like Brad Majors and Janet Weiss, the lead protagonist of The Rocky Horror Picture Show (1975), playing in that film by Barry Boswick and Susan Sarandon. The main protagonists of this film Terry, Nancy and Gloria's car breaks down during a rainstorm and they are taken in by the family living in the mansion.
The car the girls are driving appears to be a white early 80's Soviet made 4 door Lada Signet, a car that was never imported into the U.S. but was imported heavily in Canada. The majority of vehicles that appear in Unhinged happen to be either white, or whitish light colored vehicles - Perhaps a trend in Portland at the time, or just coincidence.
The radioman at the very beginning of the film states "A note to you rock n' roller's out there, if you're planning on heading up to Pinewood for the big music festival, you'd better pack some warm clothing." No mention is made specifically of a "jazz festival." And the girl's are listening to blues rock music in the car on the way there.
The trivia item below may give away important plot points.
In the trailer of the film, the scene which Terry discovers the bodies of her friends and the bodies of other victims in a shed is in slow motion. But on the Australian/New Zealand CBS/Fox video videotapes of The Rocky Horror Picture Show (1975) and Wizards (1977), the sequence in the trailer is not in slow motion.