After reading this:
I noticed in the sample file that the guide-planes for the perspective grid are drawn as solid planes.
Investigating, I found that the settings are stored in the text file "Perspective Grid Presets" in the
%USERPROFILE%\AppData\Roaming\Adobe\Adobe Illustrator CS5 Settings\en_GB directory (Win7)
Changing the values of the following to 1 in a preset (identifying takes some intelligence since they have no clear names)
gives you a perspective grid like this:
I keep now two presets of perspective grids with exactly the same settings, except the option above. Allows for easy switching between the two views.
If anyone has a way to set these options in the GUI please post.
Using the Perspective Grid tool or Perspective Selection tool, Option/Alt click on one of the three circles at the bottom of the grid plane. This will cycle between grid lines, solid colors, and no visible grid.
Thanks! That makes it of course much easier!