NVH (Noise, Vibration, Harshness) is one of the main attributes in a passenger car. One of the key systems responsible for the overall NVH behaviour is the powertrain mounting system. The optimal layout of this system leads to the definition of a stochastic optimization problem. In this paper the background of the complexity of the powertrain mounting system is highlighted. In a first approach the optimization problem is solved with Design of Experiments (DOE) methods.