The woman was offered a lift as she walked home on Saturday night in Chelmsford, on her way home from the festival.
She got into the car and was assaulted by the man, a short drive from where he picked her up.
She managed to escape and make contact with the police.
Be cautious on your way home from a festival. You’ve had a great time and chances are you’re not at your sharpest. Any official taxi service will show a plate on the rear of the vehicle and a licence with photographic identification on the driver’s side of the taxi.
If you don’t see these, don’t get in and call for help.