Buick 2011 LaCrosse Owner's Manual page 67

3-14 Seats and Restraints
Why Safety Belts Work
When you ride in or on anything,
you go as fast as it goes.
Take the simplest vehicle. Suppose
it is just a seat on wheels.
Put someone on it.
Get it up to speed. Then stop the
vehicle. The rider does not stop.
The person keeps going until
stopped by something. In a real
vehicle, it could be the windshield...