RAC Auto Windscreens has launched a 'Nothing on Display' campaign that is backed by the Home Office, which aims to encourage drivers to take their valuables out of their cars when they park them.
More than two-thirds of vehicle-related crime happens during the hours of darkness, it adds.
The company is promoting its Safe Sack, launched last winter, as a deterrent against crime. It is a drawstring bag designed to hold valuables and can be stored in a handbag or briefcase.
It also contains vital information on combating car with a list of essential security tips. A card can be displayed on the car's dashboard as a reminder to motorists to remove their belongings and as a warning to potential thieves that there is nothing left in the car worth stealing.
The sack is available free of charge from any RAC Auto Windscreens fitting centre on production of a valid driving licence.