So the other day while it's pouring rain, I'm driving to work and I catch a rock on the windshield. Didn't notice at first what with all the rain on the windshield, but it had cracked just below where the wiper is on the passenger side when it's down. IOW, just about a half inch above where the glass starts. But then it started to spread, cracking straight upwards for about 5", then making a left turn and it's about 2" long that way over the course of the next couple days. Right now it's in a pretty innocuous spot, totally out of my vision. Problem is, if I can't stop it I know I'm gonna end up replacing the glass real soon which I'd rather aviod. So... I thought I'd heard something about a product that could stop a crack from spreading. Anyone here know what it is, and if so, how effective it is? Many thanks in advance.