The paper deals with the problem of assessing the characteristics of a vehicle body on the example of a car body. Such systems allow not only to reduce the cost of design, but also to obtain a number of important estimates that are not available at the stage of full-scale tests. An assessment system based on a virtual platform and a digital twin is considered. It is shown that the acceptable accuracy of the estimates is provided by the sufficient accuracy of the mathematical model. Considerations on approaches to designing the structure of such software systems are presented. The problems of modeling and evaluation based on the digital twin of the designed product are considered. The relationship between the model, on the basis of which it is supposed to evaluate the characteristics, and the models of adjacent vehicle systems, requiring a similar approach based on a digital virtual platform, is considered. Attention is paid to the main estimated parameters of the model and limitations.