nobby

as replied earlier try zymol rear screen clean kit totally natural and applied correctly will not damage the rear screen. will reduce and remove scratches and also comes with a screen wax to protect for future use.please do not use fairy liquid as suggested, this is very abrasive and will eventually leave horrendous swirls in the screen and over a long period of time will damage it due to the chemical ingredeiants

Dracoro

IIRC the roof mechanism in the glass screen cars is different so that the roof doesn't fold where the screen is. just putting a glass screen in would probably break the first time you put the roof down.

BTW - does the glass screened roof take the same time to lower/raise as the plastic screened ones?