See also:

Brake Pedal Travel
See your dealer if the brake pedal does not return to normal height, or if there is a rapid increase in pedal travel. This could be a sign that brake service might be required. ...

Reporting Safety Defects to General Motors
In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors. Call 1-800-521-7300, or write: Buick Customer Assistance Center P.O. Box 33136 ...

Power Lumbar
On vehicles with power lumbar, the control is located on the outboard side of the front seats. For vehicles with a two-way lumbar control, press the control top or bottom to increase or decreas ...