In the US, this film is called 'Why Bother to Knock', no doubt in not to confuse it with Troublez-moi ce soir (1952), which stars Richard Widmark, Marilyn Monroe, and Anne Bancroft, and which is based on the novel, Mischief, written by Charlotte Armstrong.
When Maggie gives her elderly Scottish taxi driver directions, he responds, "Who do you think I am, Stirling Moss?" Stirling Moss is a British Formula One race car driver of the era.