A motor vehicle washing system washing brush construction, having a plurality of washing brushes associated with a support tube, each washing brush having a plate body die-cut so as to form thereon a plurality of cuts providing a corresponding plurality of contoured strips joined by a central band element, with the central band element being wound on the support tube to arrange the contoured strips on both sides of the central band element, with a pair of ring elements being threaded on the support tube, on both sides of washing brush, to clamp the central band element in order to move the support tube contoured strips away from one another and cause opposite strips to move toward another, by pairs, thereby arranging the opposite strips with a substantially 90° relationship to the support tube axis.