Thames Valley Police is appealing for witnesses following a suspected robbery in West Street, just off the Bicester Road in Aylesbury on Monday.
At around 9pm on Monday evening, the victim, a 36-year-old man, was approached by a group of men who pulled him out of his car.
The men left the scene in the stolen vehicle – a black Vauxhall Astra and another black vehicle.
The victim was not injured during the incident.
Investigating officer Detective Sergeant Kerry Bradfield, based at Aylesbury police station, said: “This incident took place in a residential area, and so it’s likely that a number of drivers and pedestrians may have seen all of part of the incident.
“I am urging anybody with any information to get in touch, as that could prove pivotal to the investigation.
“This was clearly a concerning incident, but I believe it to be an isolated one.
“I am appealing to anybody who believes they witnessed the incident to call 101, quoting URN 1423 (1/10) or alternatively you can visit https://www.thamesvalley.police.uk/tua/tell-us-about/cor/tell-us-about-existing-case-report/and provide all the details there, or call Crimestoppers anonymously on 0800 555 111.”