Do this:

Hold shift, and left click the desktop. Under "HotSpots" pick "on." Then, set the UL (upper left) to "Toggle All." Then, set the UR (upper right) to "Top-bar Z-order."

Now, when you move your mouse to the upper left corner, it will toggle the bottom elements on/off. This oddly changes the z-order of the topbar at the same time, but you can toggle that with the hotspot you just made in the upper right.