Homemade Car Chassis Design Refinement

My homemade car’s tube chassis is roughed-in inside Zoo Design Studio, but before I cut any steel I want an experienced engineer to polish the design. The job is purely design refinement: no welding or shop work, just solid engineering that gives me confidence the frame will handle real-world loads... (Budget: $15 - $25 USD, Jobs: 3D CAD, 3D Modelling, AutoCAD, CAD/CAM, Engineering Drawing, Finite Element Analysis, Mechanical Engineering, Solidworks)