NSW man sitting in car robbed by gang

A man has been robbed at knifepoint by a gang after he stopped in his luxury car on the NSW Central Coast.

The 28-year-old was approached by three men and a woman as he sat in his two-door Mercedes-Benz in Gosford late on Wednesday night.

One of the men allegedly pulled out a knife and demanded money from the driver, who handed over a sum of cash, before the four fled on foot.

Officers believe the crime was opportunistic and police are appealing for witnesses to come forward.