Abstract: Advertising or information displays can be shown on screens (10, 11) provided on walls of a van-bodied road vehicle. The displays comprise video or still images back projected onto the screens from projectors (13) located within the vehicle body (1). The projectors (13) have control units (13a) with stored digital image data connected to a local computer unit (14) which operates the projectors. The computer units (14) of different vehicles are connected by wireless links to a central management server (22) which controls operation.