Abstract: An automatic vehicle cleaning system in which a spray bar is mounted on a trolley which moves on an overhead track around a vehicle stopped at a cleaning location. Rotating spray nozzles are mounted on the spray bar to spray the top and sides of the vehicle as the trolley advances around the vehicle. An indexing mechanism is provided for adjusting the spacing between the sides of the vehicle and the nozzles which spray the sides for accommodating different size vehicles with optimal cleaning efficiency. The spray bar may be indexed to any of four positions using two different length pneumatic or hydraulic cylinders connected end to end.