This paper reports on the design, development, and use of a test rig that enables the analysis of the aggressivity of vehicle interiors to the heads of occupants. The equipment comprises a pneumatically controlled free-flight headform device. It can be positioned inside the passenger compartment of any passenger car via any normal window or door aperture. The device fires a simulated headform prescribed in SAE J984 at speeds for 10 to 30 mph. The enormous degree of flexibility in positioning enables impacts to be conducted on almost any part of the vehicle interior.Currently, energy-absorbing characteristics of the interior of passenger cars are assessed using drop rigs or pendulums, which necessitate the dismantling of the vehicle body. This has implications for representativeness in terms of the validity of the stiffness characteristics of the section of the vehicle being tested.The results of testing standard specimens, using all three test devices, are presented and discussed.