A woman was threatened by a man during the night in the car park of the ASDA supermarket in Thrum Hall Lane, Halifax.
The incident happened between 7.50pm and 8pm on Tuesday, December 22.
The victim, a 34-year-old woman, got in to her black Vauxhall Corsa after finishing her shopping and was approached by a man who threatened her and told her to get out of her car.
When the victim got out her phone to call the police the man walked away towards Spring Hall Lane.
The man is described as white, aged in his late 20s to early 30s, around 6ft tall, of slim build, wearing a dark hooded top.
Detective Constable Gordon Little, of Halifax CID, said: “We would ask anyone who saw this incident or who has any information which could help our enquiries to call Halifax CID on 101.”