An Automobile door is a complex module, which consists of various fixed and movable subassemblies and components. Its movement can be axial or linear depending on the application and vehicle design. Parameters like Safety, vehicle dynamics, aesthetic and strength are critical while designing the door assembly. Apart from the above, the design of door trim should minimize (BSR) Buzz, Squeak and Rattle at vehicle running conditions. Stiffness is one of the key engineering requirements which if not optimized to the optimal level will result in higher BSR levels and failure of the door trim components. In this paper, more emphasis is given to optimize the stiffness by studying the impact of the various door trim structures. Door trim is a part of door assembly which is one of the aesthetic assemblies in the vehicle interior. An allowable range of deflection on the plastic trim parts is considered depending upon the conditions, comfort level and location of use. It should satisfy the regulatory requirements and (DVP) Design Verification and Planning of OEMs. If stiffness is more than the requirement, the door trim plastic parts are harder and will violate the quality and safety norms. If stiffness is less, then trim parts will not meet the functional requirements and safety norms. Stiffness optimization studies of the door trim to meet optimum level are carried with various design proposals capturing different structural concepts. CAD modeling of the exemplary door trim is done by NX® software and deflection analysis is executed by solvers Abaqus®. Stiffness value is arrived as an output parameter in each analysis. Iterative design and analysis is carried out for structures until we met the optimal value. Physical testing is carried out on the initial and final optimized designs. The deflection and stiffness values are measured at different door trim locations. The virtual test results correlated well with the physical testing. This structural optimization technique is beneficial in arriving at the final design with lesser design iterations and shall be implemented across new programs.