Unhinged (1982)

College students Terry, Nancy, and Gloria, on their way to a rock concert, crash their car in a torrential rainstorm, badly injuring one of them. Seeking shelter and aid, they come across a house occupied by a man-hating mother and her daughter...and they soon wish they hadn't.

Originally passed uncut for cinema. Unhinged was on the uk video nasties list but wasn't prosecuted! Released uncut in 2004.