The world of cars is evolving rapidly, and this evolution is increasingly leading vehicles to be intelligent and interconnected. This paper aims to provide a valuable overview of cars' connectivity concerning trends and technologies. The future automotive market's challenges are now focused on this trend involving large economic investments. This article introduces the primary background concerning problems that the automotive industry must resolve to react satisfactorily to consumers' mobility demands regarding efficient services, comfort, and safety. The widespread employment of digitization in the automotive area will allow a leap forward in creating sustainable and intelligent mobility services. Greater accessibility, small and powerful computers, and the exploitation of wireless networks and cloud services will be required. More in detail, this paper presents a thorough discussion of the leading technologies useful for evolving connected cars. This growth will allow the mixture of computer and network technologies with the Internet of Things (IoT), thus offering communication capabilities at any time, from any place, with anything. This paper also aims to identify salient features of this progress, starting from the onboard diffusion of telematic components and linked to the spread of infotainment, up to some applications, such as car-sharing and smart ticketing. Finally, the main characteristics of connected cars and self-driving cars are examined, trying to trace the future development prospects for these vehicles.