In my opinion, ultrasonic repellents are the most safe for nature. In addition, some of them scare away not only mice and rats, but also insects. They do not require refilling chemicals, only electricity. There are devices for cars. For example, Vensmile Under the Hood Electronic Rat Repeller for Cars. Read this article https://smartratcontrol.com/best-ultrasonic-rat-repellents/ . It describes the most successful device models.
The one in the post above was a complete and absolute failure. They all still nested in the tractor engines and ate all the wiring including the gas tank cap. I'll go through that article you mentioned and will probably try one of them once the snow melts and mice are ready to infiltrate my property.