This is what happened to a rental Caddilac I drove a couple years ago... driving along, two lane road, pouring the rain, semi goes by in opposite direction and someting flies up and strikes the windshield so hard it practically stuns us with the sound. We didn't/couldn't stop because of traffic and the rain, but this is what it looked like the next day... note it is directly in line with the steering wheel!
Here's how it looked from outside the car...
