Cars left at the entrance to popular parks, beaches and walkways will be under the watchful eye of Summer Safe carpark monitors.
More than 50 volunteers are monitoring Whangarei District's popular beach and bush carparks.
Ross Wagner is the volunteer co-ordinator for the programme and said over the past four years he has had a lot of satisfaction out of deterring would-be thieves.
Every weekend throughout summer the Summer Safe volunteers don high-visibility jackets and watch over carparks at Whale Bay, Whangarei Falls, AH Reed Memorial Park, Abbey Caves, Mair Park, Ruakaka and Waipu Cove.
Mr Wagner said he has interacted with visitors who are grateful to return to untouched vehicles thanks to the volunteers' watchful eyes.
"It's enjoyable to talk to people from other countries and they feel a hell of a lot better leaving their vehicles when we're there.
"They always give us a 'thank you' when they come back to their vehicle and see it's still there."
Mr Wagner has seen suspicious cars approach carparks, their occupants taking a good look at the volunteers watching over the cars before turning around without stopping - a sign the volunteers are effective, he said.
Meanwhile, a group of residents from the Tutukaka Coast community, who wish to remain anonymous, donated time and money to install a security camera at the Whale Bay carpark.
They said they were sick of holidaymakers leaving the beautiful beach upset and angry after their cars had been broken into in the carpark.
Summer Safe is now on the hunt for more volunteers to pitch in to watch over a carpark.