Rear seat infotainment system for a motor vehicle (car) having an on-board bus system which provides in a wired transmittable manner infotainment data in the form of digital multimedia data which are to be displayed on a screen of a mobile device which is held in a nondestructive and reversibly detachable manner by a retaining structure provided on a back of a car seat in said motor vehicle, wherein said retaining structure comprises one or more contact interface(s) having electrical ports providing these wire-transmitted infotainment data, and wherein at least one of these contact interface(s) is connectable with a corresponding user interface having electrical contacts and provided at the mobile device in order to transfer these infotainment data to the mobile device and to display these infotainment data on the screen of the mobile device, and wherein, each, the electrical ports of the contact interface(s) and the corresponding electrical contacts of the user interface(s) are designed according to the so-called spring-loaded technology or elsewhere termed SLC technology (derived from s pring l oaded c ontacts) in order to provide probe-type connections between a number of pistons of spring-loaded contacts on a spring-loaded connector (156, 180) with a number of pad faces (16, 90, 116) of pads (10, 80, 110) on a pad connector (60, 108, 128), characterized in that - there is a first multicore electrical connector comprising a multicore electric cable having two distant ends (4 and 5), wherein a first pad connector is electrically conductive connected to the one cable end, and a second pad connector (60 or 108) is electrically conductive connected to the other cable end; and further, - there is a guide rail insertable into a backrest of the car seat and defining a tunnel which terminates in an open manner at the rear side of this backrest, and a spring-loaded connector is mounted on the guide rail in such a manner that the spring-loaded pistons of the spring-loaded contacts of this spring-loaded connector extend into this tunnel; - the retaining structure is detachable attachable to the car seat and comprises a panel having a swivel hinged slide which has an inner slide end, and an external slide end and a slide section extending between these slide ends (231 and 233), and this slide is insertable into the tunnel defined by the guide rail, and is lockable within this tunnel in a fully established position, and is again removable out of this tunnel "26) - after a locking device has been solved - in case when the restraining structure shall be separated from the car seat; - the first pad connector is inserted into the inner slide end (231 so that their pad faces contact the spring-loaded pistons on the spring-loaded connector, if the slide section is fully introduced into the tunnel; - the panel comprises - in case of regular use - an on top arranged edge having a spared groove, and the second pad connector (60, 108) is inserted into this groove in such a manner, that its pad faces (16, 90) point upwards; and - that the cable connecting the first pad connector with the second pad connector (60 or 108) is fed through the slide section, enters the panel, and is fed through the panels' interior. - there is a first multicore electrical connector comprising a multicore electric cable having two distant ends (4 and 5), wherein a first pad connector is electrically conductive connected to the one cable end, and a second pad connector (60 or 108) is electrically conductive connected to the other cable end; and further, - there is a guide rail insertable into a backrest of the car seat and defining a tunnel which terminates in an open manner at the rear side of this backrest, and a spring-loaded connector is mounted on the guide rail in such a manner that the spring-loaded pistons of the spring-loaded contacts of this spring-loaded connector extend into this tunnel; - the retaining structure is detachable attachable to the car seat and comprises a panel having a swivel hinged slide which has an inner slide end, and an external slide end and a slide section extending between these slide ends (231 and 233), and this slide is insertable into the tunnel defined by the guide rail, and is lockable within this tunnel in a fully established position, and is again removable out of this tunnel "26) - after a locking device has been solved - in case when the restraining structure shall be separated from the car seat; - the first pad connector is inserted into the inner slide end (231 so that their pad faces contact the spring-loaded pistons on the spring-loaded connector, if the slide section is fully introduced into the tunnel; - the panel comprises - in case of regular use - an on top arranged edge having a spared groove, and the second pad connector (60, 108) is inserted into this groove in such a manner, that its pad faces (16, 90) point upwards; and - that the cable connecting the first pad connector with the second pad connector (60 or 108) is fed through the slide section, enters the panel, and is fed through the panels' interior.