I could not make the 90-degree bend and then continue straight along the PVC pipe with the heat-shrink-tubing. So, I removed the middle section of PVC pipe of both mounts and then placed HST on the elbows, followed by the straight sections. I used table leg caps as end caps. I added a clamp per section [now a total of 8 clamps attach the mounts to the bottom of the cargo boxes.

To hold the flags steady, I added a clamp to each mount and anchored it to the cargo box.

The reverse fender hovering above the two cargo boxes is positioned to hold small solar panels that I'll use to maintain the taillight batteries. It is raised to allow the placement of the canopy with its solar panels attached should I need or want to remove the canopy. The attachment system also allows the cargo boxes to be opened by rotating the fender left or right.

Notice the fender base. I am mulling over placing a Slow Moving Vehicle Emblem [a triangle] 14" x 16" on the base. Your comments are welcomed.