Here's my setup on my 96 Montero.
I decided I did not want to apply adhesive backed velcro to the inside window frame area of my rig. With the heat of the southwest and CA deserts I wasn't sure how well that would hold up.
Instead I made a screen pocket (using 48" wide window screen material and 2" wide nylon straps) to put over the window section of my door. It's sewn on 3 of 4 sides with only the bottom open.
To install it, I simply slide it over the window. To seal it, I sewed magnets into the bottom seam. The magnets hold the screen well enough to the body that bugs don't get in.
Total cost for the 2 rear windows is $45 (screen material: $15, nylon webbing straps: ~$15, magnets $15). I do have enough screen to make a set for the front windows but I'd need to buy more nylon strapping.:smiley_drive: