See also:

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 ...

Side Blind Zone Alert (SBZA)
The vehicle may have a Side Blind Zone Alert (SBZA) system. Read this entire section before using the system. WARNING: SBZA is only a lane changing aid and does not replace driver vision. SBZA ...

Your Responsibility
Increase the volume of the radio if the OnStar advisor cannot be heard. If the light next to the OnStar buttons is red, the system may not be functioning properly. Press and request a vehicle ...