A straightforward approach is presented to investigate the ride dynamic system for a typical rear-drive passenger car. The procedure is based on introducing two main ride excitation sources, i.e., engine/driveline and road inputs, which reduce passengers’ comfort. The measured engine fluctuating torques are applied on the coupled model of the driveline and the suspension, to obtain the vehicle body longitudinal vibration. Further, the body vertical response to an average road roughness, is found by employing the quarter-car model. Through the frequency analysis done in this paper, it is shown that we can fastly determine the transfer functions of the systems and also their forced responses at the desired positions, without guessing any initial conditions for the states. The results illustrate that the high frequency inputs, from the engine, are appropriately damped by the current suspension. Hence, the associated vehicle body longitudinal acceleration meets the \acISO criteria. This is not the case for the low frequency disturbances, from the road surface irregularities, where the vehicle body vertical acceleration is above the \acISO criteria.