Spiders love to hide in cars, and they can be tricky to keep out. The first step is to keep doors and windows shut as much as possible, and to make sure that there aren't any gaps for them to sneak through. Next, you'll want to vacuum your car regularly to remove crumbs and spider webs. Give your car a thorough clean with a general purpose spray and then use one of the natural remedies above to deter them from coming back. Natural ingredients such as cinnamon, vinegar and citrus can be used to scent your car.