This paper presents a state-of-practice (SOP) overview of automotive communication technologies, including the latest technology developments. These networking technologies are classified in four major groups: (1) current wired, (2) multimedia, (3) upcoming wired and (4) wireless. Within these groups a few technologies stand out as strong candidates for future automotive networks. The goal of this paper is to give an overview of automotive applications relying on communications, identify the key networking technologies used in various automotive applications, present their properties and attributes, and indicate future challenges in the area of automotive communications