only thing ive used that works or putting a light on under the car and hood at all times.
my buddy has a HUGE pack rat problem. fuckers bring cholla catcus in with them and eat up everything in a vehicle. hes tried the soap trick, they just eat it. dry sheets dont do anything. sprying smells dont work or they drink the water with it in it. And noise alone doesnt really work. He put these in everything he owns and has had 0 issues since.
out at my place, i dont have a huge problem but they are out here. i put those same amazon deals on my trailers, the trucks and the tracker. Now that everything stays pretty much inside, i built traps at entry points. just a shoe box with two small openings (like 3"x3"), a small snap trap and an almond hot glued to the trigger. ive killed about 10 so far this year.