NOTE THIS IS JUST ONE ACCATCAHMENT, YOU WILL NEED TO ADD TWO OF THESE TO THE CART AND 2 rails to mount two panels. For every additional solar panel you will one more leg more rails.
Canadian-made Kinetic Solar Wall/Awning Mount, type KWN60P-G, makes it easy to mount solar panels to a wall. These are galvanized steel brackets that are fastened to a wall. Regular Kinetic Solar (Rapid-One) rail is mounted on the brackets, and panels go on top of that using regular mid- and end-clamps. The brackets work for both 60- and 72-cell panels, and the panels mount in portrait at a 60-degree tilt-angle (to the horizontal, so the angle with the wall is 30 degrees).
For Rapid-One rail one bracket is needed every 4 feet, with a maximum cantilever at the ends of 19″. the KWN60P-G brackets come as a single unit, with a set of 2″ L-brackets. The hardware to mount to the wall, or rails and other panel mounting hardware is not included. To mount a single panel you would need two KWN60P-G brackets, and for more panels they would simply be spaced every 4 feet (just like regular L-brackets on a roof solar installation).