That's absolutely NOT the case and that advice could and would kill you. It also helps to explain my point, so thanks.

If you're trapped in your car underwater, breaking any of the windows except maybe whichever one is above you will lead to practically instant death. And the fact that your windshield and windows don't break under the extreme pressure of however many hundreds or thousands of kilos of water are pushing on them is the only reason you might survive.

Water is heavy, cars are not buoyant in water. If your windshield broke while your car was underwater, that weight would be pushing on you directly, and it's incredibly unlikely you'd survive that.

Movie scenes where people break the window and swim out are fake. That will kill you.