From DiYLife :
To those of us who have to drive every day (and on the freeway, no less), we end up with a smattering of bugs all over the front windshield that can not only drive us batty once we try to use that auto-wiper function to clean all that muck off, but can actually impair vision.
...............Note: Be careful here, razor blades are dangerous instruments. But, if used with a holder/handle system (you can get these for a dollar or two at any hardware store), light scraping or just sliding that razor blade gently down the windshield will make those bugs easily come off and reveal a nice and clean windshield, perfect for more driving without those annoying visual distractions right in front of you.