Two men stole the car after robbing two shops, where they threatened staff with hammers to steal cash and cigarettes.
Two women, aged 88 and 37, have been left “terribly shaken” after armed robbers took their vehicle with them in the back seat.
Police are investigating following the “violent” incident in Stourbridge on Sunday.
It came after two masked men first raided the One Stop convenience store on Hungary Hill, where they threatened staff with hammers shortly after 9pm.
A getaway vehicle waiting for the men stalled, officers said, leading them to turn their attentions to the victims’ parked Ford Mondeo.
The suspects made off in the car without noticing the two women in the back seat.
They were dumped on the roadside several yards further on after the robbers realised they were in the vehicle. The car then sped off towards Lye.
Investigating officer Sergeant Richard Narrowmore, from West Midlands Police, said the same men had also raided the Co-op in Glebe Lane, Norton, in similar circumstances less than an hour before the incident.
In both robberies, the suspects made off with cash and cigarettes.
Speaking about the car-jacking, Sergeant Narrowmore said: “The younger woman was slightly injured and both of them were terribly shaken by their ordeal, so we are keen to trace these men as soon as possible.
“These were violent attacks with little thought for their victims and they need to be brought to justice quickly.”
The stolen vehicle was recovered a short while later in Bromley Street, Lye. Forensic examinations are under way on both the stolen vehicle and the abandoned car, a silver Volkswagen Golf.
Officers are going through CCTV to see if they can identify the men.
:: Anyone with information is asked to call police on 101.