What do you want to bet the car is designed, built, and tested in a climate controlled human comfortable environment. Perhaps the high temperatures alter the spring rate or extension, the viscosity of certain lubricants, or tensile/ductile properties of some critical suspension component, the result being that the parts/fluids test perfect in the lab but change to unacceptable under high temps.
What do you want to bet the car is designed, built, and tested in a climate controlled human comfortable environment. Perhaps the high temperatures alter the spring rate or extension, the viscosity of certain lubricants, or tensile/ductile properties of some critical suspension component, the result being that the parts/fluids test perfect in the lab but change to unacceptable under high temps.