The complexity of electrical and electronic systems in cars has grown drastically during the past decade. Model-based function design and simulation are widely used by the Automotive E/E community today in order to manage this complexity. Emerging new standards, such as AUTOSAR, define standardized interfaces to low-level software and most importantly introduce a new level of abstraction to function implementers. This improves the reusability of software components. Unfortunately, there is little guidance on how to translate the results of model-based function design into robust and efficient system implementations in a highly distributed environment. This paper outlines a proposed system level design methodology, covering architecture design, scheduling of networks and tasks distributed across multiple ECUs, harness design and metrics generation.