You are making incorrect assumptions. Just because they made a window bigger or a member longer doesn't mean it's weaker. They could have changed the material

You are making incorrect assumptions. Just because they made a window bigger or a member longer doesn't mean it's weaker. They could have changed the material to something twice as strong, added hidden structures, etc. The difference is mandated crash testing, and now simulated crash testing. They are required by law to build cars that are safe, and test to make sure they truly are.