Plastic on the Spiders, glass on some TB's/TS's, and some sort of lightweight polycarb on the 348 Competiziones.
mine is a 1990 TB and is plastic and has gone white on the edges. I have spooke to a dealer today and they said a new one is £1600 and is glass but he could do me a plastic copy one for £300 ?? Confused or what !
It is apparently fairly common for the rear window on the 348 tb/ts to de-laminate around the edges, which can make it appear to turn white. I imagine if you had your old window to use for a pattern, you could have a plastic/Lexan sheet bent to match the curvature and dimensions, but it wouldn't have the embedded defrost wires. Installation labor is probably pretty stiff as well.
