mixer 14 of the third module 12 are connected to the control manager 15 and are controlled by it the task of the control manager 15 involves in particular the controlling of the units connected to it in such a way that upon occurrence of a warning or error signal for example the outputting of the audio and or video or holographic data received from the external unit 2 is prevented replaced or supplemented in order to tell the driver about a critical vehicle condition for example for this purpose the control manager 15 realizes a suitable output such as a sound a text or a pictogram on the display 5 and or the loudspeaker 4 a warning or error signal may be provided to the control manager 15 for example by the first module 8 e g low level of the fuel tank engine temperature critical and so on or the second module 11 e g battery alternator defect diagnostic defect seatbelt not buckled etc the control manager 15 then decides for example per predetermined priorities whether and how to notify the driver in an alternative mode of operation the warning or error signals of the second module 11 may also be sent directly to the display.