The NHTSA issued an Advanced Notice of Proposed Rule Making (ANPRM) during the third quarter of 1988. Research tests on a mid-size car and a light truck upper interior surfaces were conducted using a NHTSA research test procedure to help assess the variables associated with this procedure. As a result of these tests, the authors recommended a revised test using a spherical headform with normal-to-surface impacts. This revised procedure was used in a second test series on a similar mid-size sedan. The results of these tests are shown.