My curse - mice and chipmunks. No rats. I've tried many, many methods. Water filled bucket trap works well in the summer. Pill bottle with drilled holes, filled with Peppermint oil saturated cotton - in the glove box, works. Traps of all sizes and baits, works also. Scented dryer sheets in all cubby holes in my Taco Wagon works. 12 gauge shotgun on fleeing chipmunks works.
They all work - for a limited time. What is working for me, right now - and has for over a year and a half - knock on wood - leave the hoods open on all my vehicles. Last spring and summer, last winter, this spring and summer and into fall - Taco Wagon( 2018 Ram 2500 Power Wagon) parked right near the house. I can look out the kitchen window and check. Not a single rodent in the engine compartment nor in the passenger area. I have the hood open on the tractor and ATV also. These two are out in the carport.
They seem to dislike the open/exposed area of the engine compartment. Yes - clearing snow on the Taco Wagon is a tad more difficult with an open hood. But I will gladly do all of that over chewed wires.