In present-day motor vehicle development processes, the acoustic design of interior trim mainly relies on experimental data and on the experience of vehicle acoustics engineers. A valuable supplemental tool for enhancing the understanding of the acoustic behaviour of trim is analytical simulation. By using the Finite Element Method (FEM), it is possible to analyse the trim within the frequency range of the second engine order and to optimise its design. In a two-year research project carried out by the Acoustic Competence Centre Graz (ACC) in conjunction with industrial partners Magna Steyr, Graz, and AVL List GmbH, Graz, in-depth studies were performed to determine the acoustic effect of trim parts in the interior of the car and the FE modelling required for the numerical analysis.