See also:

Customer Assistance Offices (U.S. and Canada)
Buick encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail Buick, the letter should be addressed to: United States Buick Customer ...

OnStar®
If the vehicle has OnStar and you subscribe to the OnStar services, please refer to the OnStar Terms and Conditions for information on data collection and use. ...

Adjusting the Treble, Midrange, and Bass
1. Press the TONE button. 2. Select Treble, Midrange, or Bass. 3. Select the value. Press the BACK button to go back to the Tone Settings menu. ...