I cut my acrylic to size and then kept them in place by using offset mirror clips.
The thicker offset part holds the window against the screen and the other end fits
down into the channel that goes around the opening. Because the clips are made
from clear plastic they're not very noticeable. It makes for a solid feel and the
windows are easy to remove when not needed. The clips are made by Anchor and can be bought at most hardware stores.
2011 Jay Feather Select 28U
2007 Silverado Crewcab LT 6.0L
Happily married and father of
two university students.