Rodents have been eating the wires of cars forever. This is not a recent phenomenon. All of my 6 cars range from 1980-2000 and most of them have had an infestation at one point or another and I have repaired chewed wires in a couple of them. I've heard soooooo many stories from old people of mice getting into cars and eating wiring, it's been a problem since we've had cars.