A spoiler is a horizontal bar that is designed to disrupt the smooth flow of air behind the vehicle. It is placed at optimum height to reduce the most drag. The spoiler is held up by a mechanism that may be made from different materials depending on the type and model of the spoiler. The factory style spoiler is of course a single design that does not change for a particular model. For example, the factory spoiler on a Nissan Maxima will always look the same. The spoiler may be made from ABS plastic, fiber or carbon fiber depending on which vehicle you own.