Rodents May Have Flavor Fetish For the Wiring Insulation in Newer Vehicles

Matt Posky
by Matt Posky
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rodents may have flavor fetish for the wiring insulation in newer vehicles

Shortly after the dawn of new millennium, automakers started implementing bio-plastics made from corn starch, genetically engineered bacteria, or vegetable fats and oils. The rationale for this was that sustainably sourced materials were better for the environment and lowered dependency on petrochemicals. Unsurprisingly, bio-plastics gained in popularity at roughly the same time as ethanol.

Since at least 2010, soy-based bio-plastics have been a popular alternative for wiring insulation in automobiles. But there’s a problem — rodents love how it tastes. This has allegedly resulted in a surprisingly high number of owners reporting that rats chewed through the wiring inside their automobile.

While the problem isn’t entirely new, the frequency of the incidents appears to have been spurred by automakers using more palatable materials. In fact, the issue has grown so bad in recent years, numerous lawsuits have cropped up demanding manufacturers pay for damages. Honda was named in a suit from two years ago involving 2012 to 2015 model year vehicles, and Toyota was hit with one for cars produced between 2012 to 2016.

Bio-plastics were in widespread use at this point. Both Kia and Hyundai were named in subsequent rodent-related lawsuits, and practically every major manufacturer uses plant-based plastics on at least a few models built within the last decade. It sounds benign but, considering that rats eating your car typically isn’t covered under a vehicle’s warranty, owners have to shell out hundreds if their insurer isn’t interested.

According to the Detroit Free Press, the growing rat problem isn’t the result of paranoia, either. John Pappas, owner of Main & Hudson Service in Royal Oak, Michigan, claims he sees at least one vehicle every month with gnawed-on wires. “They’re going environmental on the wires,” he said. “There’s good and bad in everything. It is a common issue.”

Jim Stevens, a sales representative at Suburban Ford of Ferndale, stated finding rats chewing through wires “is a pretty common thing around here,” with around two or three vehicles coming in a month.

Brian Kabateck, a Los Angeles attorney is involved in a class-action lawsuit against Toyota Motor Sales, filed on behalf of an Indiana resident who watched his 2012 Toyota Tundra become a meal for rodents three times. Total damage was estimated at roughly $1,500, which Kabateck said Toyota won’t cover.

“Our contention, why soy is certainly — it’s laudable — they’re trying to be more green, at the same time, it’s becoming a potential food product for rats,” the attorney said, adding he’s not looking to make everyone rich. The suit is simply seeking reimbursement for damages and a new policy that would cover rat-damage under Toyota’s warrantee.

However, we don’t need to take the word of lawyers or service center employees. Owners are are willing to express their concerns on practically every online automotive forum. A cursory search for the term “rat” in numerous brand forums returned dozens of first-hand accounts from affected owners. Vehicles range from a Nissan Versa to a Jaguar XKR, but the vast majority share one common trait — they were built after 2005. Maybe it’s not telling, as fewer owners are worried about older cars. Still, there are decidedly fewer mentions on older threads.

Toyota claims rodent damage to vehicle wiring occurs across the industry, and the issue is not brand- or model-specific (which is true). It also noted that it was not familiar with any scientific evidence that rodents are attracted to automotive wiring due to alleged soy-based content.

Neither are we, but that isn’t stopping the public’s growing worry. Entire websites are devoted exclusively to tips on how to keep rats from eating car wiring. In the Free Press article, Janice Perzigian witnessed rodents do $600 worth of damage to her 2017 Ford Mustang. As a result, she takes time out of every day to surround the car with Pine-Sol, stuff the interior with dryer sheets, and spray down the tires with essential oils.

Forum solutions are frequently just as elaborate, often including plots to kill the varmints before they can get comfortable inside the engine bay. Our favorite reoccurring recommendation involves coating every single centimeter of wiring with hot sauce on a weekly basis.

[Image: Holger Kirk/Shutterstock]

Matt Posky
Matt Posky

Consumer advocate tracking industry trends, regulation, and the bitter-sweet nature of modern automotive tech. Research focused and gut driven.

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  • Redmondjp Redmondjp on May 18, 2018

    When I was on the VW forums 10-15 years ago, this problem came up, and somebody found out that VW in Europe offered an actual factory anti-rodent wiring harness option (complete with a picture of an actual rat biting on a wire, right in the option brochure - imagine ever seeing that in this country!).

  • Stingray65 Stingray65 on May 18, 2018

    I wonder if the wiring on a Tesla is covered with this stuff - might lead to some char-broiled rats and mice, and some lawsuits by the EPA or the Interior Department for violating the endangered species act - at least until Trump can drain the swamp of all the Obama holdovers.

    • See 2 previous
    • ToddAtlasF1 ToddAtlasF1 on May 19, 2018

      @30-mile fetch Were any of the lies in your dream world whoppers like the ones Obama told to destroy our healthcare system? Were they told in an effort to nuclearize Iran? Were they told make people hate one another irrationally?

  • 285exp If the conversion to EVs was really so vital to solve an existential climate change crisis, it wouldn’t matter whether they were built by US union workers or where the batteries and battery materials came from.
  • El scotto Another EBPosky, "EVs are Stoopid, prove to me water freezes at 0 degrees Celsius" article.It was never explained if the rural schools own the buses or if the school bus routes are contracted out. If the bus routes are contracted out, will Carpenter or Bluebird offer an electric school bus? Flexmatt never stated the range of brand-unspecified school bus. Will the min-mart be open at the end of the 179-mile drive? No cell coverage? Why doesn't the bus driver have an emergency sat phone?Two more problems Mr. Musk could solve.
  • RICK Long time Cadillac admirer with 89 Fleetwood Brougham deElegance and 93 Brougham, always liked Eldorado until downsized after 76. Those were the days. Sad to see what now wears Cadillac name.
  • Carsofchaos Bike lanes are in use what maybe 10 to 12 hours a day? The other periods of the day they aren't in use whatsoever. A bike can carry one person and a vehicle can carry multiple people. It's very simple math to figure out that a bike lane in no way shape or form will handle more people than cars will.The bigger issue is double parked delivery vehicles. They are often double parked and taking up lanes because there are cars parked on the curb. You combine that with a bike lane and pedestrians Crossing wherever they feel like it and it's a recipe for disaster. I think if we could just go back to two lanes of traffic things would flow much better. I started coming to the city in 2003 before a lot of these bike lanes were implemented and the traffic is definitely much worse now than it was back then. Sadly at this point I don't really think there is a solution but I can guarantee that congestion pricing will not fix this problem.
  • Charles When I lived in Los Angeles I saw a 9-5 a few times and instanly admired the sweeping low slug aerodynamic jet tech influenced lines and all that beautiful glass. The car was very different from what I expected from a Saab even though the 900 Turbo was nice. A casual lady friend had a Saab Sonnet, never drove or rode in it but nonetheless chilled my enthusiasm and I eventually forgot about Saabs. In the following years I have had seven Mercedes's, three or four Jaguars even two Daimlers both the 250 V-8 and the massive and powerful Majestic Major. Daily drivers of a brand new 300ZX 2+2 and Lincolns, plus a few diesel trucks. Having moved to my big farm in central New York, trucks and SUV's are the standard, even though I have a Mercedes S500 in one of my barns. Due to circumstances with my Ford Explorer and needing a second driver I found the 2006 9-5 locally. Very little surface rust, none undercarriage, original owner, garage kept, wife driver and all the original literature and a ton of paid receipts and history. The car just turned 200,000 miles and I love it. Feels new like I'm back in my Nissan 300ZX with a lot more European class and ready power with the awesome turbo. So fun to drive, the smooth power and torque is incredible! Great price paid to justify going through the car and giving her everything she needs, i.e., new tires, battery, all shocks, struts, control arms, timing chain and rust removable to come, plus more. The problem now is I want to restore it and likely put it in my concrete barn and only drive in good weather. As to the writer, Alex Dykes, I take great exception calling the 9-5 Saab "ugly," finding myself looking back at her beauty and uniqueness. Moreover, I get new looks from others not quite recognizing, like the days out west with my more expensive European cars. There are Saabs eclipsing 300K rourinely and one at a million miles and I believe one car with 500K on the original engine. So clearly, this is a keeper, in love already with my SportCombi. I want to be in that elite club.