Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil.
The recommended oils with the dexos specification and displaying the dexos certification mark are all that is needed for good performance and engine protection.
Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.
See also:
XM Radio Messages
XL (Explicit Language Channels): These channels, or any others, can be blocked at a customer's request, by calling 1-800-929-2100 in the U.S. and 1-877-438-9677 in Canada.
XM Updating: The encryption ...
Pairing
A Bluetooth&-enabled cell phone must be paired to the Bluetooth system and then
connected to the vehicle before it can be used. See your cell phone manufacturer's
user guide for Bluetooth ...
Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and
GPS signal reception. Cellular reception is required for OnStar to send remote signals
to the vehicle. ...