The Skoda Octavia Ambiente was one of the most secure cars

It took them eight seconds to get into a Fiat Panda Dynamic and 11 seconds to enter a Kia Pacinto SE in the survey of 20 new vehicles for What Car? magazine.

But some cars proved much more impenetrable - they could not gain entry to two BMW models, a Lexus and a Peugeot within two minutes.

The testers used readily available tools and did not damage the vehicles.

Most secure of those tested BMW 525i SE - No entry Lexus RX300 SE-L - No entry Peugeot 407 SE - No entry BMW X3 SE - No entry Skoda Octavia Ambiente - 1 min 57 sec

What Car? said that although the British Crime Survey suggested car crime was 12% down in 2003-04, there were still more than 1.3 million thefts from cars each year.

Car crime accounts for almost 15% of all recorded crime.

What Car? editor David Motton advised motorists to consider the results of the security tests before they bought new vehicles.

"Car security is far better than a decade ago, but there are still some popular cars on sale with weak locking systems," he said.

Least secure Fiat Panda Dynamic - 8 sec Kia Picanto SE - 11 sec VW Golf GT - 26 sec Smart Forfour Pulse - 31 sec Mazda RX-8 - 39 sec

He also urged people to "use your common sense" and not to leave valuable belongings such as mobile phones, laptops, jackets or shopping bags on display in their cars.

"Where possible, put them out of sight in the locked boot or take them with you," he said.

"Always lock your car and activate the alarm and immobiliser where fitted."