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In-vehicle subjective evaluations of a mid-sized SUV exhibited an objectionable vibration character when driven over smooth road surfaces with minor rolling irregularities. As a result, a project was initiated to systematically identify problem frequency components and degrees-of-freedom that contribute to the phenomenon sometimes referred to as “nervousness.” The Ford Vehicle Vibration Simulator (VVS) was used to simulate the vibrations felt on the road. Eleven degree-of-freedom (DOF) simulations were produced. The seat simulation contained three translational (vertical, lateral and longitudinal) and three rotational (pitch, yaw and roll) DOFs. The steering wheel consisted of all three translational components in addition to the DOF associated with wheel rotation. The floorpan was excited in the vertical direction only. By systematically eliminating various DOFs, it was determined that the seat contributed the most to the objectionable vibration.