State laws differ but in general yes, most states require an auto insurance company to give you advance notice that they will not be renewing your car insurance policy.

For example in Oregon if your policy has been canceled or "non-renewed" for a reason other than nonpayment, the company must give you at least 30 days’ advance notice. An explanation of the reasons for the cancellation or non-renewal must be part of or accompany the notice.

In California an auto insurance company must give a policyholder at least 45 days notice prior to the policy expiration if they do not plan to renew their policy. An insurer shall deliver to the named insured or mail to the named insured at the address shown on the policy and include the reason or reasons for the non-renewal.

In Washington State insurance car companies are required to give a twenty (20) day written notification regarding the non-renewal of a personal auto policy and a ten (10) written notification for cancellation due to non-payment of premium.

To find out what your state insurance laws require of an auto insurance company that is deciding not non-renew your policy contact your state's insurance regulator. They should be able to tell you how much notice the insurer has to give you of the non-renewal and what other information must be part of the notice, typically the reason of the non-renewal needs to be listed.