Nova Hughes, 24, a trainee buyer for Marks and Spencer, was grabbed at knifepoint in a supermarket car park in Shepherd's Bush, west London, last Saturday afternoon and forced into the boot of her hatchback car.
She spoke for the first time of her ordeal yesterday, just hours after a similar attack a few miles away.
"There was a hand on my mouth and a knife by my throat. A guy said `I have got a knife, I want the money'," Ms Hughes told a news conference yesterday.
"I put my hands down. He got behind me and he told me to get into the boot." She told her attacker that she was scared and suffered from claustrophobia and begged him to let her go.
"I told him I didn't want to get in but he forced me in." Her ordeal ended about 45 minutes later when the 6ft man ran off, leaving the boot open, after withdrawing pounds 200 from her bank account with her cash card.
Ms Hughes appealed to anyone who saw the man in the car park last Saturday to come forward.
"I think he has done it before. The whole time he was completely in control. When I panicked he told me to calm down. I think he could do it again," she said.
NCP, which owns the car park, has offered a pounds 5,000 reward for information leading to the man's arrest. It has promised a review of the security at the car park.
A carbon-copy attack occurred at 10.30pm on Wednesday in Hampstead, north London, when a man snatched a 54-year-old woman from the street, took her bank cards and locked her in her car boot.
The woman suffered a cut face. She was forced to hand over her bank cards and PIN numbers and driven around for 80 minutes before being freed in an underground car park.
Last night James Nicholas Pierre, 29, unemployed, of Manor Park, east London, was charged with kidnapping a woman of 54, robbery and aggravated taking and driving away of a vehicle.