Motor vehicle collisions often involve the engagement of vehicles with varying height structures leading to underride/override collision dynamics. As such, using standard flat barrier impact tests to determine crush stiffness directly may lead to over-estimations as primary load absorbing / dissipating structures may not be directly engaged. Further, underride/override impacts have been shown to have longer crash pulse durations, leading to reduced peak accelerations and forces to the vehicle and occupants. The subject study involves a pair of override impacts to the rear structure of a sport utility vehicle (SUV) with measured changes in velocity of 4.9 and 11.7 miles per hour. The impacting surface was a simulated ICC bumper of 4-inch by 4-inch cross-section, such as that typically found on the rear of many commercial trailers. Damage profiles were documented using a 3D laser scanner and then crush measurements were completed using the original undamaged profile. The crush stiffness calculated was significantly less than that of reported full-height barrier rear bumper impacts for similar SUV’s. This study provides a method for determining a scaling factor to the reported rear crush stiffness in the event of an underride/override impact, and specifically the scaling factor for the subject SUV. Additionally, an instrumented 50th percentile Hybrid III anthropomorphic test device (ATD) was seated in the front passenger seat and a nearly 50th percentile male volunteer in the driver seat. The ATD was equipped to measure acceleration and forces in the head, neck, chest, lumbar spine and pelvis. No injuries were sustained by the volunteer, and injury assessment reference values were not exceeded in the subject impacts.