Abstract: A system for mounting signage onto the door area of a vehicle is disclosed. The system includes a mounting assembly and a display substrate. The mounting assembly includes a series of brackets operable to capture the display substrate against the panels of a roll-up door system. Specifically, the brackets may include an upper bracket mounted to the uppermost door panel, a lower bracket mounted to the lowermost door panel, and a plurality of side brackets each selectively mounted to one or more of the door panels. The substrate is configured to flex at predetermined points to accommodate the pivoting of adjacent door panels during the opening/closing of the door.