We all have that stuff. The guys above are right. It's from layer separation.
Of course you could scrub REAL hard, and maybe in 200 years you could actually make it through the first layer and finally get to the stuff, but of course the whole windshield would be like that then. :P
Start planning to get a new one.
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'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.
*See pics of my trucks and project at
www.webshots.com!