Zebra zone windscreen

[banpei]

Last week when I was out for a drive wearing my new sunglasses, I noticed my Trueno has a zebra-zone windscreen. A zebra-zone windscreen is one that has been tempered with heat to ensure it's more resistant to stone chips and this creates an oily radiator-like pattern on the glass under certain angles. I remember seeing this for the very first time on my dad's Carina when I just washed it and the windscreen was still wet.
I never noticed this before on my car with or without my old sunglasses, but due to the polarizing filter in my sunglasses, it became very visible all of a sudden. It may sound like a stupid question from my side, but do all AE86-es have this or is this an indicator my windscreen has been swapped?