See also:

Speedometer
The speedometer shows the vehicle's speed in either kilometers per hour (km/h) or miles per hour (mph). ...

Customer Assistance Offices
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 — Customer Assist ...

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) ...