Usually to find out if a car has insurance on it you have to go through a state agency. It may depend upon the reason that you are requesting this information as to what state agency can help you.
The best place to find out is through the individual that should hold insurance on an insurable interest.
For example if you were in an accident with a person and need to enquire about the other party's insurance provider then like you would need to go through your state's insurance regulator or if your state has a financial responsibility unit or division. With these you would normally submit a crash or accident report and request insurance information on the other party if none was provided to you at the scene of the accident.
If you were involved in a hit and run and have the type of car and a license plate number then your local law enforcement office may be able to guide you through making a report and finding the right state agency that can help you obtain information on the car owner and their auto insurer.
Your state's Department of Motor Vehicles may be able to help if you have the name of someone, the license plate number or the VIN of a car and need information on auto insurance regarding this vehicle. If your DMV is unable to help you find out if a certain car has insurance on it then they should at least be able to direct you to the state agency that can help you obtain this information.
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