One-third of all vehicles broken into in residential areas had been left unlocked by the owner, An Garda Síochána said this morning.
Gardaí are today appealing to motorists to "park smart" in an effort to help reduce crime.
Figures from the Garda Analysis Service released today show that 8,571 vehicles parked at residential locations were broken into between 2015 and 2017. Of those, 2,824 were reported to be unlocked.
The analysis also shows that the most common location for these thefts was in driveways, and that half of the thefts occurred between 12midnight and 7am. Such thefts are happening throughout the country.
On average, over €340,000 worth of property was stolen from vehicles each year.
Property stolen included cash, laptops, tools, sunglasses, jewellery and sports equipment.
Gardaí are appealing for all vehicle owners to ensure they lock their vehicle no matter where it is parked and to avoid storing valuables in the car, and to keep them out of sight when they have to be stored.
Sgt Kelvin Courtney from the Garda Crime Prevention National Centre of Excellence said: "Wherever you park your car or van, we would always advise you to take your property with you and ensure the vehicle is locked, alarmed and parked in a secure, well-lit location.
"Many of these thefts, particularly at residential locations, are avoidable with an average of 33% of vehicles being left unlocked in the last three years.
"Unfortunately, this poor practice has risen as 38% of vehicles were unlocked when they had property stolen from them in January 2018.
"Sometimes it is impractical to remove tools and equipment from vehicles. In these cases, owners should take extra steps to ensure the safety of their property.
"Additional locking mechanisms to vehicles should be fitted.
"Consider a monitored vehicle alarm and tracking devices for valuable property. Reduce the payoff to the thief by marking and photographing the property and take a record of serial numbers, makes and models.
"Download the household property register for free from the Garda Website for your records.”
According to the Garda Stolen Motor Vehicle Investigation Unit, the vast majority of cars illegally entered or stolen from are done so using the vehicle’s key. The vast majority of vehicles stolen continue to be taken with keys obtained in burglaries.
An Garda Síochána’s advice surrounding any vehicle keys would always be to avoid leaving them on the hall table or near a door/window where they could be easily taken.
Gardaí also released a regional breakdown of thefts from unlocked vehicles between 2015 and 2017.