Road breakdown staff are being kept busy at beaches around the country, going to the rescue of absent-minded holidaymakers.
The Automobile Association says callouts to popular coastal spots are soaring, with almost 60 per cent involving flat batteries, starting difficulties, or keys locked in cars.
"Because they're relaxed and in holiday mode, people quite often make mistakes they wouldn't normally make," said AA Roadservice national manager John Healy.
"Our service officers and contractors have accessed a number of locked vehicles to retrieve car keys that have inadvertently been left in the boot after people have dropped their keys inside while they're unloading bags or getting beach gear and picnic baskets out."
The top trouble-spot for holidaymakers with car trouble is Mission Bay in Auckland, where the AA has logged 56 callouts since December 21.
Others in the AA's top 20 include Bucklands Beach (43), Whakatane (42), Thames (38), Red Beach (38), Whitianga (35), Tairua (34), Raglan (34) and Papamoa (30).
AA Roadservice officer Larry Harbott said congestion heading north through Auckland was the worst he has seen in his 36 years in the job, making it more challenging to reach some holiday spots.
"At times it's been difficult to access Shakespear Regional Park and Wenderholm Regional Park (north of Auckland) because of the queues of cars lined up to get in," he said.
"People are certainly making the most of this good summer weather by heading to the beach."
Mr Healy said people do not need to be AA members to phone for help if animals or children became trapped in locked vehicles.