If there is any water more than about a third of the way up, there will be too much force to open it. Also, the electric motor will actually work under water as fresh water is a poor conductor of electricity. Unbuckle everyone inside, wait until the cabin is almost full of water, roll the window down and swim out. Check it out on Mythbusters.
Wow. Thanks for the info.
During the time all in the car are in a total panic I have to calmly try to see if my ignition key will turn on the system to get the window motors to work.
Maybe like Planes, Trains and Automobiles as the car submerges I can say the John Candy line after the car burned —”One thing, the radio still works fine.”