I've often used my windshield and other windows to help determine the longevity and durability of Klasse (both SG and AIO)
If your window is Klasse free (or make it so by cleaning it before hand), put some SG on it, the method we mostly use (waiting to buff) and then do it on another window the new way (buffing right away).
It'll put a thin single layer of SG and you'll be able to determine how washing and the elements treat the glass (and they'll be side by side)
It's your best best at getting a good comparison accurately.
So go to it :xyxthumbs
If your window is Klasse free (or make it so by cleaning it before hand), put some SG on it, the method we mostly use (waiting to buff) and then do it on another window the new way (buffing right away).
It'll put a thin single layer of SG and you'll be able to determine how washing and the elements treat the glass (and they'll be side by side)
It's your best best at getting a good comparison accurately.
So go to it :xyxthumbs