Actually, we were going to mention this to a friend of ours who has been in the glass/screen business for over 30 years!!  He made us some aluminum ones for our regular Vanagon that we attached by velcro to the outside of the windows and they worked great.  Aluminum frames all around.  We just needed to improve on the velcro since they stopped holding pretty good sometimes and would fall off when the velcro got loose.  We're seeing him this coming week and we were going to mention them to him.  He loves doing that kind of thing!!

Sharon Mendonca
88 Vanagon GL
88 Westy