When my father-in-law's beloved Volvo began running roughly, he brought it into the shop. The technicians discovered rats had been chewing through the wiring. This puzzled my father-in-law, as over the years he'd parked other cars in his driveway, and none of them had attracted rats to the wiring; why the Volvo?
He subsequently learned that Volvo had switched over to an eco-friendly, biodegrable wire coating made from soy. As it turns out, this soy coating is apparently quite tasty to rodents. A Forbes article on the subject reveals that some owners of late-model cars made by Volvo, Honda, Mazda and Toyota have experienced the same problem. "The common denominator appears to be soy," the article states, noting that lawsuits have been filed. "Alas, no green deed goes unpunished."
The article reveals that owners of the affected vehicles have been taking matters into their own hands:
"[Volvo owner] JoAnn conducted an exhaustive Google search and discovered a new rat repellent: Coyote urine. She bought a supply of the Coyote formula from Home Depot for $24 -- plus shipping. Every night, JoAnn pours a little coyote piss around her tires. 'I dot my driveway with some too,' she says. She also places a Coyote urine-soaked sponge inside a tin pan near the car. She's not sure it's working yet and does not want to take her car in for any more repairs until she's rid of the rats once and for all."
Any manufacturers reading this: Please consider my wife's suggestion, which is to offer in-car snakes as an option.