Cobber

A glass screen reduces the rear view, whilst with a new plastic version you will have the original field of vision.

Yes but the glass screen remains clear unlike the plastic one which only retains it clarity for about 5 minutes before it goes opaque,
The glass may offer a smaller view and the plastic offers a larger but blurry view……six of one and half a dozen of the other
Most Fs and TFs I see have battle scars on their arses, this is undoubtedly due to poor rearward vision with the roof up
If you wanna see what behind you get a reversing camera!