Advertise on the move! personalized with your services and contact information, car magnets are an effective marketing tool. Our square auto magnets are weather-resistant, durable, flexible, and infinitely repositionable. Each of our car magnets will stay where you put it, but will also peel off when you need to remove it. Magnets are 30 mil. Magnet backed vinyl with rounded corners. Keep your message in front of your clients on a daily basis while you drive around, car magnets make great car signs.