Property worth £1.6m was stolen from vehicles in Northern Ireland in the past year, according to police figures.
Thieves stole £1.6m of property from cars in NI in past year
The most frequently targeted item was audio equipment followed by tools, car parts and handbags.
Research also showed that almost half of thefts took place in residential areas, followed by 24% in car parks and 23% at the roadside.
There were 5,371 thefts from vehicles in NI between September 2004 and August 2005, down from 7,506 the year before.
Police believe many of the thefts would be prevented if motorists took some simple steps to safeguard their property.
"If you leave valuables on view in your car or van, whether it's outside your home, in a street or a car park, then you are inviting a thief to come and take them," Assistant Chief Constable Judith Gillespie said.
"A thief can strike in a matter of seconds. If they see it, they'll steal it.
"But if motorists took just a couple more seconds and put their valuables out of sight, they'd substantially reduce their chances of having their vehicle broken into.
"Motorists can help themselves by following these simple steps: park in a secure place or well-lit location; if possible, remove the stereo or at least its faceplate; remove valuables and personal possessions; lock bulky items in the boot; and, finally, the most basic step of all, lock all windows and doors," she said.