I have a "Worst Case Survival Book" that I like to read sometimes. The book has a section about escaping a car in water! You want to try and open the window as fast as possible - before you hit the water, if you can. The pressure on the outside of the car will be HUGE once you're underwater so you want to open the window as fast as possible. Keep yourself buckled in so you're held in place until you're read to exit. You won't be able to get out with all the water coming in so wait until the water is up to your chin. Take several deep breaths and then hold one. Unbuckle and push yourself out of the car. If you don't know what way is up, that's ok. You can float to the top - your lungs are like a balloon with all the air. If you can't open the window before (or right after your in the water) you can try to break a side window (windshields are harder to crack). There are tools you can get for the car too - I bought one after reading my book. It's like a little hammer on one end to break windows and has a razor (protected) on the other to cut you out of a seatbelt in an emergency. I hope that helps!