To file a complaint against a car dealership in Massachusetts, you can: 

• File a complaint with the Attorney General's Office
• You can file a complaint online at https://www.mass.gov/how-to/file-a-consumer-complaint or by calling the consumer hotline at (617) 727-8400. The hotline is open Monday through Friday from 8 AM to 4 PM. 
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• Research the dealership
• You can check the dealership's licensing status with the licensing board in the city or town where it's located. You can also check the Better Business Bureau for reviews and complaints. 
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• Contact the police or licensing authority
• If the dealership is involved in activity you want to report, you can contact the police or licensing authority in the city or town where the vehicle is located. 
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• File a claim against the dealership's surety bond
• Every dealership should have a surety bond, which is a form of protection for consumers. If the dealership doesn't fulfill their end of the bargain, you can file a claim against their bond.