A woman has been left shaken after she was the victim of a car-jacking in Suffolk in which her Porsche was stolen.
The blue Boxster S was being driven by the woman on the A140 at Stoke Ash on Tuesday evening.
She stopped in a layby after the car behind flashed its lights and the female passenger pointed to the front of the Porsche.
A man then opened the driver's door, threatened her and she got out.
He drove off in the Porsche towards Diss.
The woman was shaken but unhurt and ran to a nearby pub to raise the alarm.
Two bags containing items including cash, a watch, a mobile phone and clothing were also in the Porsche.
The man who stole the car was in his early 30s with fair hair and a straight fringe. He was wearing a dark coat.
The female passenger is described as having dark hair in a scruffy ponytail. The car they were in is thought to have been white.
Det Insp Karl Smith said: "Such incidents are rare, but I would urge all drivers to be aware of their surroundings and keep windows and doors locked when their vehicle is stationary.
"If you are being signalled to stop by another vehicle, only stop if you are safe and happy to do so.
"Call police if the other driver's behaviour is threatening or putting you at risk, or drive to the nearest police station."