Car manufacturers are constantly looking for new options to make the vehicle more attractive to the customer. In terms of design, this is usually done in the middle of a model's life cycle, when a so-called facelift of a production model is carried out. This involves small changes to the shape of the bodywork to improve the design of the vehicle until it is time for a new model range. This paper discusses a case study that focuses on the modification of the rear body components of a ŠKODA Superb III in Combi version. The aim of the study is to assess how the proposed modifications will affect the aerodynamics of the vehicle. The most significant changes concern the rear spoiler and finlets. The aerodynamic properties are assessed based on CFD simulations that are performed for a series production and a modified variant of the vehicle, and the results of which are compared and discussed.