Abstract: An audio system for vehicles, in particular for motor vehicles, comprises a device component (A) permanently fixed to the vehicle, and a mobile component (B) connected to the device component in a mechanically detachable way. The device component further comprises a control unit (1), and the mobile component further comprises a transponder for storing a numerical code. The function of the audio system is interrupted when the mobile component is removed from the device component, and resumed, following an authorization check, when the mobile component (B) is replaced. The authorization check is performed by the control unit which further comprises a comparator unit (2) for comparing the numerical code transmitted by the transponder (T) with a security code previously stored in the device component.