If you find yourself in a sinking vehicle, the first step is to not panic and to remove your seat belt and anyone else who may be in the vehicle. It is important to remember DO NOT try to save personal belongings, the more time that is taken to grab items puts your life at serious risk.
Most vehicles will not sink immediately, if you have time, get out of the vehicle immediately. If you find yourself stuck in the vehicle with rising water, do not try to force the doors at this point, as the outside pressure of the water will make it extremely difficult to open. Instead roll up windows and unlock doors and move to the highest point in the roof where air will be trapped. As water fills the inside of the vehicle the pressure will equalize. At this point tell everyone to take a deep breath, open the doors and as you swim to the surface remember to exhale slowly as you rise. If there are multiple individuals leaving the same door it is important to be connected with one another through linking of arms or holding on of clothing. If you have a small child they should be in the hands of an adult and the first one out of the vehicle.
*Due to the nature of the accident medical services should be notified immediately for trauma as well as hyperthermia.