The occurrence of various vibrations and noises in an automobile, such as idling vibration, boom noise and road noise, is greatly affected by the natural vibration modes and could be developed for controlling the body strength and weight these problems could be solved and a high-performance vehicle realised.This paper presents an analytical method developed by the authors to solve these problems and gives examples of its application.In developing this method, the problems of natural vibration mode and static stiffness control were addressed. Perturbation and sensitivity analysis methods have already been proposed for mode control. Four typical methods were examined and the best one was chosen in terms of accuracy and calculation time when handling large-scale problems.For static sensitivity analysis, we proposed a nevi method which is like natural mode sensitivity analysis. As a result, complex optimisation problems, namely, the simultaneous optimisation of stiffness and natural mode, can now be analyed in short CPU running times.This paper gives actual examples in which the methods chosen for mode and static siffness control were applied to reduce body vibration. These examples show how the new analytical method can be used for concurrent control of the first and second body bending modes and its stiffness.