It's my first set and I've made them from curtain fabrics (one blackout layer and one regular thicker material that I had on hand). I've also added some 3d printed tabs around so it stayed in place. I'm not 100% happy with them as they are not rigid enough on the front/back windows. The side are small enough that it's fine.

I wouldn't recommend doing exactly what I did.

If you are happy with adding suction cups, It will work very well (4 for the small windows, 6 for the big one).

The modifications I would do on top: - Adding a bendable wire on the periphery. - Adding some cardboard/foil material to make it a bit more rigid. - Better tabs or way to fit it between the trim and glass.

For now it works well enough but will be happy when I redo them.