Thin walled frames are prevalent in automotive body structures as they provide lower vehicle weight to meet strength and stiffness requirements for different type of loading cases. Reducing body weight improves fuel efficiency. The inner and outer styling surfaces drive the shape of the design space which constrains structural configurations and size of parts. Although automotive structural engineers have been using thin walled frames for years, they are keen on getting improvements through topology optimization. This paper focuses on development of a set of methods that automate the process of creating hollow cross-sections for body components inside the design space. Lofting these cross-sections along the load path of each component results in a surface model which can be used in FEA for verification and later in designing joints between different components. The starting point of this methodology is the curve skeleton, which is a 1D representation of the load paths within the design space. By analyzing the load paths, planes normal to the curve can be created to cut the design space to obtain the 2D wireframe of the boundaries. Predefined parameterized cross-sections created based on experiential knowledge that are stored in our cross-section tutor, can then be mapped to reside inside the design space boundaries at these different cutting locations. Several test cases are presented to discuss the capabilities and limitations of the tool. Future work on expanding the software to include more functions is also presented.