for my car, I have a rid a rat. It's a device that hooks up to the battery and emits a bright led light to make under the hood an unpleasant place to be. Not infallible though--one time, I had a mechanic come over to check out an unrelated trouble code (the emissions system), and in opening the hood, saw that my rid a rat got disconnected! a mouse chewed the wire that connected to the battery, I think he must've paid for that with his life. There were some mouse droppings near the battery. It's been reconnected and no further incidents.Someone told me that they make a type of tape to put over car wires that repels rodents. It tastes terrible to them. I haven't checked into this because they said it's pretty expensive, but maybe a roll of that would be cheaper than replacing wires.