Using Smell
Another method that’s less risky is using the distinctive smell of a predator in order to scare off squirrels. According to CWF, sprinkling pet hair or placing an open bag of used kitty litter in your car works.
Intimidating
“The squirrel will likely feel intimidated by the smell,” they explained. The main point to keep in mind is that whatever you spray or put inside your car, make sure not to damage it. Take that advice from your mechanic, or you might as well just leave it to the squirrels.