See also:

Tires
Use a stiff brush with tire cleaner to clean the tires. Notice: Using petroleum-based tire dressing products on the vehicle may damage the paint finish and/or tires. When applying a tire dressing, ...

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

Reporting Safety Defects to the United States Government
If you believe that your vehicle has a defect which could cause a crash or could cause injury or death, you should immediately inform the National Highway Traffic Safety Administration (NHTSA) in addi ...