I've got cats, but like others mentioned, they love climbing & jumping on cars & will scratch the paint. I have to keep the cats out of the garage, but started finding rodent droppings all over the garage & inside 2 of my cars. I bought a 3 pack of electronic pest repellers from Harbor Freight for $7.99 when I was ordering other stuff.
I figured it was a cheap way to try to keep them out. If it didn't work, it wasn't a lot of money. The droppings decreased quite a bit, but I still found them in places, so they appear to help a little, but not completely. I bought 2 boxes of the stinkiest drier sheets I could find & put them all over.
I used the entire box inside 5 cars & all over the shop. I put them behind the work bech, in corners, & where ever else I could. I did that recently, so I don't know the outcome. Drier sheets smell better than moth balls, but they do feel like they can leave a film of somekind, so be carefull where you place them. I have them in the trunk, the floors, the dash, under seats, & the car.
Now I put them inside spare parts boxes & seats in the loft after I saw more droppings. These d**n rodents are all over.