Currently, the topics about HUD systems are strongly going inside on the automobile industries; consequently, there have been proposed new ways to understand and apply this technology in an economically viable way. To contribute to this situation, this paper presents a case study which sets out key parameters that should be considered on the design of an HUD, how can be configured these parameters, and how they are related. Finally, it is presented an optical design alternative that meets the main requirements of an HUD system applied to mid-range automobiles. There are several ways to cover the development and construction of HUD systems, the method here proposed is raised to provide and to understand the factors involved in this technology and the popularization of it on the automobile industry.