Today I was driving down the highway and I ran over a rock that hit somewhere between the two front wheels. It hit so hard that the car made a huge thunking noise and started smoking. I immediately pulled over and stopped. When I pulled over the car was leaking massive amounts of transmission fluid. It had left a streak of transmission fluid up the road. I couldn't see much except there was a scrape on something. The best case scenario would be I damaged the cover. I drive a 2007 cobalt that just passed a clean inspection a month ago. The car has 40000 clicks and has an automatic transmission. I havn't started the car since in fear of further damaging the transmission. I have taken pictures and will put them up once I figure out how. Any advice on what happened? I wish I knew more about cars and I can't find a diagram of the bottom view of the car anywhere. Help would be much appreciated!