A module electronic device, for example a car radio, a navigation system or a radar detection system, comprising a fixed module fitted with external electrical contact elements, which is to be mounted on a wall, for example a dashboard, and a detachable module fitted with electronic components and external electrical contact elements, which detachable module can be connected to the fixed module in such a manner that the external electrical contact elements of the two modules are interconnected, wherein the fixed module and/or the detachable module comprise(s) at least one magnet, such that the detachable module can be connected to the fixed module through magnetic force.