This article presents a study on reconstruction of a crash of a passenger car – Opel Mokka, into a pillar. Computer simulations were performed with software V-SIM4, both for default data and data identified from the crash test. The crash test was performed by AUTOBILD and DEKRA. The frontal collision with a pillar is not a standard crash test recommended by the Directives of Communaut´e ´Economique Europ´eenne (CEE), even though this type of collision poses a serious threat to the safety of vehicle users. The threat comes from the large penetration of the vehicle body through the pillar. These accidents are difficult to reconstruct with the programs applied by expert witnesses, because they require a lot of experience and changes in many parameters. Identification of these parameters is critical in this case. Values of the parameters were identified from recorded images. The obtained results of simulation show strong sensitivity of the accident course to the position of the force application point, which acts between the pillar and the vehicle. Also, the key factors are: contact parameters, identification of the initial conditions, sensitivity of the course of the accident to the adopted values of the parameters, and knowledge of the limitations of any software. Many expert witnesses do not even realise that their results of simulations, based on default values, are faulty. The process of obtaining an agreement between the simulation and experimental results is a time-consuming iteration process. This process is described in this article, which is address to expert witnesses and researchers; moreover, a direction for development of software was suggested.