Abstract: A method of customer-individualized adjustment of a car radio having a microprocessor control and corresponding internal operating software, an interface for changing the operating software and an external memory device that can be read by the interface being provided. A selection is made from various software modules for different functions of the car radio, this selection is stored on the memory device, the memory device is connected to the interface in order to start operation of the car radio, and the software modules stored on the memory device are loaded into the car radio as an extension of the operating software.