Impacts to the vehicle interior are the most frequent source of occupant injury in highway accidents and generate the largest segment of the resulting total harm as calculated by the National Highway Traffic Safety Administration. Accordingly, improving the injury-mitigating properties of interior components along with the structural integrity of vehicles has significant potential for providing important safety benefits to occupants of crash-involved vehicles. This paper reviews the relative contribution of various occupant-vehicle contacts to total harm and offers some insight into the benefits that might be realized through component improvements. While such improvements are related primarily to unbelted occupants, their benefits should be considered complementary to those of safety belts and airbags since (1) some degree of nonuse of belts likely will remain even with the growing adoption of belt-use laws in the United States, and (2) belted occupants still can contact the vehicle interior in more severe crashes, as can occupants of airbag-equipped cars involved in crashes below the deployment threshold or in side impacts and rollovers.