Michigan Compiled Laws, Chapter 500. Insurance Code of 1956 § 500.3018

Sec. 3018. (1) An authorized insurer that issues automobile insurance policies in this state and issues an insurance policy to a shared vehicle owner insuring a shared vehicle may exclude all coverage afforded under the policy for any loss or injury that occurs during a car sharing period, including, but not limited to, all of the following:

(2) This section does not require a shared vehicle owner's automobile insurance policy to provide coverage while the shared vehicle is operated during a car sharing period.

(3) This section does not preclude an insurer from providing coverage for a shared vehicle, including, but not limited to, by contract or endorsement.

(4) An insurer that excludes the coverage described in subsection (1) does not have a duty to defend or indemnify for any claim that is expressly excluded. This section does not invalidate or limit an exclusion contained in a policy, including a policy in use or approved for use in this state before the effective date of this section, that excludes coverage for vehicles made available for rent, sharing, or hire or for any business use. This section does not invalidate, limit, or restrict an insurer's ability under existing law to underwrite a policy or to cancel or nonrenew a policy.

(5) An insurer that defends or indemnifies a claim arising out of the ownership, maintenance, or use of a shared vehicle that is excluded under the terms of the insurer's policy may seek recovery from the insurer of the peer-to-peer car sharing program if the claim is made against the shared vehicle owner or the shared vehicle driver for loss or injury that occurs during the car sharing period.

(6) As used in this section, “car sharing period”, “peer-to-peer car sharing program”, “shared vehicle”, “shared vehicle driver”, and “shared vehicle owner” mean those terms as defined in section 3  3 of the peer-to-peer car sharing program act.