When I first tried with a razor blade, I was getting tiny pieces of paint to fall off from higher up the windshield. When I tried the main area, the blade wouldn't dig in at all. I could definately tell something was there, just could not get under it with the blade. Yesterday, I tried Fast Orange (mild abrasive) and window cleaner with steel wool. That area feels a lot smoother than before, but the the discoloration doesn't seem any different.
The area doesn't bother me much, it's just annoying having to look at it. And it doesn't help that my seat sags enough that it's in my line of sight. It's silly, here I am over 6 feet tall, yet I feel like a granny who's barely tall enough to see over the dash!