I recently restrung our 4-string day/night shade behind our jack knife sofa in our 05' Journey. It appears as though the valance had screw mounts on either side (angle brackets) and also screws in to the ceiling. However, the shade had to first be removed to access the valance ceiling screws. So, I couldn't remove the valance and therefore I had to remove and reinstall the shade which made the process quite difficult. I could be wrong, but I saw no other way to remove the valance w/o first removing the shade.
Did I mention how much I hate those darn day/night shades?
cheers,
Joopy