A car sinking in deep water poses one of the most difficult survival challenges that a family can face. There have been some realistic video's and tests done on this situation - they show that you've got very little time to do the right things and survive. It would be much harder still for a family minivan where there are both parents and kids in the vehicle.

Yes- the conclusion was to punch out the vehicle windows with a sharp tool. Fortunately the side windows will shatter. But you have to take this step VERY quickly. And as someone also noted, in a multiple-occupant situation you would really need to punch out several windows. I'm not sure kids could do this in a scary situation (or at all), so a parent would have to somehow get back in the vehicle. Hard to do ... maybe not impossible. But probably one of the most stressful experiences that a parent or adult would go through.

Pete