carnage1 is correct about rolling down the window; however, this is easier said than done under many circumstances. Years ago I started to drive onto a frozen lake at night to do some snow plowing and had an odd feeling. So I rehearsed what I would need to do if I went through the ice. As I was snow plowing on the lake 30 minutes later, I thought that the truck became stuck (in reality, the truck actually broke through the ice and was sinking, but it was night and I could not tell.) I shifted between forward and reverse several times still not realizing that I had broken through. Finally after realizing that truck was sinking, I tried to open the door; however, it would not budge. Next, I opened the window and crawled out onto the ice and watched as the truck sank 10 seconds later.
The truth is without the rehearsal of what I would need to do just prior to sinking the truck, I would be dead. It is hard to describe the disorientation experienced at night and having to accept that the door would not open. Once submerged in water, I doubt that it would be possible to locate the hole in the ice even if I did manage to get out of the truck. I estimate that it took less than a minute for the truck to sink. A minute seems like a long time; however, it is not very long to make decisions when you are disorientated unless you have practiced.
