General Information
For service and replacement parts, contact your dealer. You will receive genuine GM parts and service personnel trained and supported by GM. Genuine GM parts have one of these marks:

See Battery - North America and Jump Starting - North America and back cover.
California Perchlorate Materials Requirements
Some vehicle applications, such as airbag initiators, seat belt pretensioners, and lithium batteries contained in Remote Keyless Entry transmitters, may contain perchlorate materials. Special handling may be required. For more information, see www.dtsc.ca.gov/hazardouswaste/perchlorate.
Accessories and Modifications
Adding non-dealer accessories or making changes to the vehicle may affect the vehicle's operation and safety, including such items as airbags, braking, stability, ride and handling, emission systems, aerodynamics, durability, and electronic systems such as the Antilock Brake System (ABS), Traction Control System, and Stability Control System. These accessories or modifications may even cause a malfunction or damage that is not covered by the vehicle warranty.
Damage to suspension components caused by changing the vehicle height from the factory settings is not covered by the vehicle warranty.
Damage to vehicle components resulting from modifications, or installation or use of non-GM certified parts, including control module modifications or software modifications, is not covered by the vehicle warranty and may affect the remaining warranty coverage for the affected parts.
GM accessories are designed to complement and function with other systems on the vehicle. See your dealer for vehicle add-on accessories. Using genuine GM accessories installed by a dealer technician is recommended.
Also refer to Adding Equipment to the Vehicle with Airbags.
Test yourself
A quick GMC Terrain quiz: every answer comes with an explanation and a link to the manual page.