The 18-year-old woman approached a blue Mitsubishi Pajero in First Tower at around 1 pm yesterday which she thought belonged to her friend.
The male driver offered her a lift to town anyway and she accepted.
On the way, it is alleged that the man indecently assaulted her before she managed to get out of the car at the People’s Park.
The driver is described as a dark European with a strong accent.
He was in his mid to late 30s, slim with short, close cropped black hair.