663.

 At least 20 days prior to policy expiration, an insurer shall deliver to the named insured or mail to the named insured at the address shown in the policy, either of the following:

(a)   A written or verbal offer of renewal of the policy contingent upon payment of premium as stated in the offer.

(b)  A notice of nonrenewal of the policy. That notice shall contain or be accompanied by a statement that upon written request by the named insured, made not later than one month following the expiration of the policy period, or delivered to the insurer, the insurer will notify the insured in writing, within 20 days of his request, the reason or reasons for such nonrenewal.

(c)  In the event that an insurer fails to give the named insured either an offer of renewal or notice of nonrenewal as required by this section, the existing policy, with no change in its terms and conditions, shall remain in effect for 30 days from the date that either the offer to renew or the notice of nonrenewal is delivered or mailed to the named insured. A notice to this effect shall be provided by the insurer to the named insured with the policy or the notice of renewal or nonrenewal. Notwithstanding the failure of an insurer to comply with this section, the policy shall terminate on the effective date of any other replacement or succeeding automobile insurance policy procured by the insured, or his agent or broker, with respect to any automobile designated in both policies.

(d)  The insurer shall not be required to notify the named insured, or any other insured, of nonrenewal of the policy if the insurer has mailed or delivered a notice of expiration or cancellation, on or prior to the 20th day preceding expiration of the policy period.