Promotional decals are a form of advertising when you drive around town. Add your logo, contact information, services, hours of operation and/or message to expand your customer reach. Car decals are put on the vehicle to either decorate it, express a catchy message, or advertise a business. Decals are resistant to environmental factors that may impact the appearance of labels, especially if they are used outdoors. However, there are instructions to maintain the longevity of promotional decals and to prevent any flaw from forming.