JC Whitney has some front window screens, magnetically attached to the door
frame, @ $34.95 for a pair.

You could also contact Triad Magnetic Van Screens in Winston-Salem, NC,
(910) 769-2427.  I have a friend who has happily used a set of their
screens on his Westy for several years.  I think #VS109 is their part # for
front Vanagon screens.  They may also have screens for the side windows,
but you will have to ask them.

Of course, you can always make your own by hot gluing some magnetic strips
to fiberglass screen mesh which has been cut to the desired size.

Budd Premack
86 Syncro, 73 Super
Minneapolis, MN (Land of Sky-Blue Waters)