The victims, a man and a woman, were driving along Knowles Hill Road at around 1.30am on Sunday when the first suspect stopped their car in the middle of the road.
They believed the man was in distress so opened the driver's window to offer help.
It was then that he leaned through the window, produced a knife and demanded that the 21-year-old female driver get out of the car.
Two other men then approached the passenger side of the car, dragged the 18-year-old male victim out of the vehicle and threatened him with a knife.
All three of the suspects got into the car and drove off in the direction of Healds Road.
Detective Inspector John Charlton, of Kirklees CID, said: "This was an extremely distressing incident for the two victims and thankfully no one was seriously injured.
"As well as the car being taken in the robbery, the victims had their laptop, an iPhone and iPod which were inside the car, also taken.
"Our enquiries are ongoing and I would strongly urge anyone with information or anyone who recognises the men described to get in contact with police.
"I would also ask anyone who saw a black Audi A3, with registration plate RV12, driving in the area at this time or who has seen the car driving in the area since, to also get in touch."
The first suspect, who spoke with a local accent, is described as white, in his mid-twenties to early thirties, with scars down his cheeks. He was wearing a blue jacket and had a tattoo on the back of his left hand, which resembled a compass.
The second man, who wore a black jacket, is described as mixed race, in his early thirties, 5ft 7in and skinny. He had short, black, scruffy hair and short stubble.
The third man was white, 5ft 7in, slim and in his late twenties to early thirties. He had a scar on his face near to his chin and was wearing a bright blue jacket.
Anyone with information is asked to contact DC 1165 Chris Eglen at Kirklees CID on 101, quoting crime reference 1317018654.