I think it sounds simpler than it is. The replacement glass must be laminated to be safe. That is different than tempered glass, which can shatter into a million shards (pointed at your face, even tho it's not supposed to). Our tempered shower door glass shattered and it was painful and ugly. And typical laminated glass for sale here in the states is too thick to fit in the Caterham windshield frame, as I recall from the last time this issue came up here.
Kitcat:AKA, Sir Spinsalot
'97 Caterham Super Sprint, 1700 Crossflow-sold
'09 Birkin S3, Duratec-sold
'03 Caterham Zetec track car
'19 Honda Type R, sold
'19 Miata Clubsport