The "theory" is, if you run your car off the road into a lake, you should wait until the car submerges before you open the doors...waiting for the pressure to equalize. Top Gear tries this, it's pretty interesting...

http://www.youtube.com/watch?v=yADmpA1XFvw






...just incase you don't watch the video, read this. The car hits all the way to the bottom of the lake before the pressure equalizes...not what you want to happen. You should really open the door and get out as fast as possible.

 

Well I guess I should just try to keep my car out of the water.

 

no more driving in the lake for me. good video tho.

 

That was a cool demo. Man would that suck in reality.

 

Stupid Brits!