The incident occurred on Cotton Road in the Wincheap industrial estate around 3.15pm on Tuesday, January 24, 2023.
The victim, a man in his forties, was sitting in a parked van when the door was forced open and a man threatened him with violence. The suspect took the keys to the van as well as two other vehicles.
The suspect walked away, followed by another man and a woman, all of whom proceeded in the direction of Cow Lane.
The suspect was described as a white man between the ages of 35 and 40, standing around 6 feet 2 inches tall and sporting a scruffy short ginger beard. He was dressed in a brown flat cap, a dark coat, dark pants, and dirty white sneakers.
The two people he left the scene with were described as a similarly aged white man, 5 feet 10 inches tall, with a short black beard and wearing a dark blue flat cap, and a white woman wearing a dark grey hooded jacket.
Anyone who witnessed the incident or has information or dash cam footage that could help investigators should contact Kent Police at 01843 222289 and quote case number 46/14611/23.