Magne Shade is the hot setup but waaay to expensive. (overpriced).
Most of us already have shades that we have to do the ladder and twist lock routine in order to install. So with all that I have modified mine by having pockets sewn on for holding a mounting stick, rod, handle or whatever as well as sewing neodymium magnets in to pockets at the proper places to support the screens across their top. Use super glue to mount magnets inside the windows and/ or windshield in the corresponding locations. Magnets are not necessarily needed along the bottom of the screens as we are using our old setup with the twist locks which in most cases if not all are accessible from the ground. I use an old broom handle that I turned the end down on for placing the screen on the magnets. As for magnets they are available all over the internet in every size shape thickness and power you may want. Be careful when you get them and play with them. They will slam together when you least expect it and they'll take the meat off your fingers to the bone.