As Electronic Control Units (ECUs) and embedded software functions within an automobile keep increasing in number, the scale and complexity of automotive embedded systems is growing at a very rapid pace. Hence, the automotive industry has been developing the AUTomotive Open System ARchitecture (AUTOSAR) to harness the reusability of common interfaces to communication buses, real-time operating systems and services. These common interfaces foster ease of adoption, interoperability, maintainability, predictability, and analyzability. However, realizing such standards also requires strong support from end-to-end design tool chains. In this paper, the authors describe some key analytical components that together characterize the end-to-end timing properties of hierarchical bus structures composed of FlexRay, CANbus and LINbus.