Express Down Feature
WARNING: This page is about a different car, the 2010 GMC Canyon and 2010 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
The drivers window has an express-down feature that allows the window to be lowered fully without continuously holding the switch. Pressing the front of the switch past the first position will activate the express-down mode. The express-down mode can be canceled at any time by pulling up on the switch.