Three years ago, I needed a windshield replaced. On a road trip last weekend, a rock flew up and hit the windshield, immediately cracking it, with a line about 6" long spread from the impact point. Within a day, that crack spread, another crack formed, and both were curving across the windshield and spread from top to bottom, or roof to hood.
I've never seen a crack spread that quickly. But thanks God Windshield Replacement Redwood City 650-492-4650 replaces my windshield, they are OEM dealer glass, and they gave me a special offer.