Future cars' architecture will be based on networked electronics. Designer of such networked systems envisage a new class of highly sophisticated complexity. Therefore a new class of appropriate system design support tools is required. This paper describes a full set of such tools, consisting of a Network Simulator, a Network Emulator and a Network Analyzer. The Simulator is used for system layout purposes without the need for actual system's hardware. The Emulator replaces in real time real system's component. The Analyzer is used for verification of the system's layout in the actual real system. As network is the backbone of future cars' systems network development tools are fundamental for efficient cars' system design.