I am personally in favor of non-permanent solutions. The windscreens really suck to have in while you have the top up, or a hardtop on.
I zip-tie the mesh inserts, and have been thinking about drilling a small hole in the windscreen, and zip-tying it to keep it as-well. This way they can be removed when you put a hardtop on. Having them out greatly greatly increases your rearward vision, and on the average day I leave the mesh inserts out because they don't do anything and block your vision.
Just my opinion!
