A Manawatu woman is upset Mazda didn't pay to fix her six-month-old car after rats got under her bonnet and chewed through her electrical wiring.
In the United States, Honda and Toyota have reportedly faced lawsuits over their use of an environmentally friendly biodegradable soy-based coating on some components, which rats apparently find more tasty than regular plastic.
The woman, who asked not to be identified, said she first realised something was wrong with her new Mazda CX5 when it started losing power soon after leaving home.
"So I pulled over and stopped the car and started it again and it was all fine. I drove another 400m down the road and all these little lights came up and I thought, oh goodness, something's wrong with the computer."
She took her car back to the local dealership to be fixed and was told rats had chewed through the wiring.
She was informed the $1500 worth of damage was not covered by her warranty because it wasn't a fault with the car, she said.
She wanted to know if her car had been fitted with the soy-based coating causing problems in the US and, if so, what Mazda was going to do about it.
"It could have started a fire, who knows, and if the manufacturer is aware that they're using soy-based products that are attractive to rodents, why are they not telling the consumer or putting rat deterrent in the car?
"How many other people has it happened to and nobody has done anything about it?"
Automobile Association spokesperson Phil Collings said he wasn't aware of any problem with soy-based coatings until contacted by RNZ, but was investigating the matter to see if there had been an increase in rat attacks as a result.
But he said rodents chewing through wires in cars was not uncommon, especially in rural areas and during winter when they were looking for somewhere warm to sleep.
Problems sometimes arose when people used poison to take care of the unwelcome visitors, he said.
"This can actually make the matter worse because the rats go looking for water and a lot of the time they'll attack the water systems in the car, for example the window-washer water bottles.
"They'll actually chew through these to get the water out of them. A lot of people won't know until they actually go to use the car and find that it's not working. In some cases there's actually been electrical fires."
Dog and Lemon Guide editor Clive Matthew-Wilson said rats chewing through wires could result in hefty bills for owners of new cars, which were now highly reliant on electrical components.
"It can literally run into thousands because you're replacing an entire section of wiring, it's like rewiring your house and if two wires happen to touch that shouldn't touch, it can also cause extreme damage."
And as for who is responsible - the owner or the manufacturer - the news is not good for car owners, according to Consumer's Sue Chetwin.
"Rats can chew through pipes in houses and in that situation you probably don't have any come-back on the plumber who put in the pipes or the pipe manufacturer, and this is really similar to that in some respects.
"You've got to actually look after your property and that means making sure there's no vermin there."
In the Manawatu woman's case, her insurer did cover the damage, but Ms Chetwin said people should check their policies, as this was not always the case.
Mazda New Zealand did not return RNZ's calls to request an interview.