At around 4.45pm on Sunday (3/4), a red Vauxhall Astra, which is believed to have been stolen, was involved in a collision with a dark grey Audi A4 at the junction of Roebuck Avenue and Hick Farm Rise.
The three occupants of the Astra, described as men wearing all black, made off after the collision.
A passenger in the Audi, a woman in her eighties, was trapped in the vehicle before being taken to Stoke Mandeville Hospital, where she remains in a stable condition.
The Audi driver, a man in his seventies, was uninjured but his vehicle has been written off.
PC Dawn Seston, of the Roads Policing Unit based at Amersham police station, said:
“I am appealing to any witnesses, or anyone who may have information about this incident, to please come forward.
“If you have any CCTV footage or any dash-cam footage if you were in the area around the time, I’d also ask that you check any recordings in case it has captured something that could assist our investigation.
“You can make a report by calling 101 or via our website, quoting reference 43220143688.
“Alternatively, you can report information anonymously to the independent charity, Crimestoppers, by calling 0800 555 111 or via its website.”
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