## 1 Introduction  
Technological processes of processing especially thin sheets in the automotive industry are often associated with excessive deformations of components, which on the one hand may not be dangerous in terms of safe and reliable operation, but their presence is undesirable from a visual (esthetic) point of view. Undesirable deformations are related not only to technological operations of cutting and processing but also to residual stresses in materials [1; 2; 3]. With the introduction of automation to technological processes, car manufacturers are trying to introduce new elements to control the geometry and shape of components in order to ensure trouble-free assembly or minimization of errors during handling [4; 5; 6]. The achieved accuracy affects, for instance, the quality of component joints in terms of required strength and functionality, etc. The paper describes the analysis of the occurrence of excessive deformations, which were identified during the installation of the roof antenna. Figure 1 providesexamples of various locations and methods of antenna mounting. When studying Figure 1, it is clear that the attachment points of antennas are different in terms of size and shape of the plate. Each manufacturer tries to implement their own \"Know How\" in their products and thus create products which are unique not only at first glance, but also in production and assembly technology. As different antenna shapes are created depending on the design or functionality, different types of mounting for the respective antenna are also created. The size of the antenna shape depends on the possibility of its use, whether it has a built-in GPS receiver or a basic AM/FM receiver [7]. The two antenna-mounting procedures are shown in Figure 2. The first is the attachment of the upper part of the antenna inserted into a predefined hole by locking the screw mechanism from the underside of the roof (Figure 2a). The second possible alternative is to attach the antenna, which consists of two parts--the core and the cover--with screws from the underside of the body (Figure 2b). At first glance, the installation of a roof antenna is a simple operation, but during its realization, visible deformations may occur, which will ultimately significantly affect the customer's first impression when buying a car. On the other hand, it should be mentioned that the price to achieve a perfect shape and surface is often too high and therefore it is necessary to find a compromise (boundary) between perfection and acceptability. Figure 1: Examples of roof antennas—different sizes, shapes and locations. Figure 2: Examples of different variants of antenna mounting: (**a**) first variant; (**b**) second variant. Constant demands on the innovation of the body shape from the customers' side brings several problems for the designers; it is possible to include the design of technical solutions that can be used for several car models without significant changes. Adjusting the shape and dimensions of the roof is one of these components, because it is made of thin sheet metal, which needs to be reinforced in selected places. The places, shape and method of attachment of reinforcing elements must be consulted not only with the production technologist, whether the proposed solution is technically possible to produce, but also with the economist to assess the economic side of production, etc. To reduce excessive deformations, reinforcement elements are most often used, the shape and method of attachment of which are currently designed primarily using the means of numerical modelling. A car body, however, is a complex construction, where every small change can cause considerable complications in the assembly process. Therefore, where possible, experimental measurement tools based on different physical principles are used to verify the results of numerical modelling [8]. As for the dimensions or shape of inspected components, laser methods are most often used.