By the looks of your problem bite the bullet and buy a new windshield, you are only wasting your money and time trying to get it out. I worked with the cerium oxide for a whole weekend on some minor scratches, just wasted my time no improvement at all. Note the trying these suggested methods while the window is in the car can result in catastrophic results. The glass can over heat when buffing and shatter be careful. speaking from experience its not worth it. New glass is available from Auto Metal Direct and a few other parts suppliers I would check it out. Find yourself a auto glass installer thats been in business for a while, this is not a DYI project. just a 2 cent opinion from someone who,s been through the same situation.