Why the Center Vertical Line in Rear Windshield?

[SUN02591]

The rear windshield of my KR FB has a subtle center vertical line, which aligns with the spine that forms in the roof section and the trunk lid.  I believe the rear windshield was manufactured by Corning.

Was the center vertical line in the rear windshield just for aesthetics to continue the spine line between the roof and the trunk lid, related to the rear window manufacturing process, or related to defrosting?

Thank you very much for your time and assistance in advance!

Don Pealer

[Coralsnake]

Not relating to defrosting .

I think its Ford glass

Corning did convertibles

[SUN02591]

Much appreciated for the clarification that it was Ford glass for FB rear windshield and had nothing to do with defrosting!

[Coralsnake]

I am pretty sure the defroster option was not used on any 1968 Shelbys.

It was comprised of a fan and ductwork that mounted above the trap door