This paper aims present information regarding Automotive Body in White (BIW) development fundamentals, providing a link between physics fundamentals and real automotive development. An introduction about product development process will be shown in order to allow the reader comprehension about timeline decision process.A properly revision regarding applied loads, body in white materials, safety and virtual/physical validation will be covered. Structural fundamental knowledge has a key role of Design Engineer background mindset to achieve challenges vehicle targets about cost, mass and performance.The paper information provides a clear technical reader understanding how product engineers use structural fundamental theories to design BIW in real design development application.A study of case regarding Front-end tie-bar was used. A real vehicle load application was simulated by CAE analysis. The engineers analyzed the results and proposed design changes based on structural fundamentals. The final results presented a mass reduction of 9.2% achieving the stiffness target performance of 400 N/mm.