This study examined automobile vibrations by using a half vehicle model, and its vertical and angular vibrations were suppressed by means of the nonlinear adaptive control of a magneto-rheological damper. The control method was designed in such a way that it did not need to measure the road input to suppress the vibrations by the use of adaptive road observers. Therefore, disadvantages such as measurement difficulty and cost were also eliminated. Instead of completely experimental test rigs, the hardware-in-the-loop simulation which is a hybrid method was preferred due to it being easier to set up, cheaper, and also it had a close response to the full experimental system. The experimental responses obtained by the proposed adaptive control method with adaptive road observers and the nonlinear adaptive control method in which the road disturbances were measured were compared in the time and frequency domains. Finally, the effectiveness of the proposed method was shown using some figures, root mean square values, and performance indices.