Mich. Comp. Laws § 500.2458
Each rating organization and insurer that makes its own rates, within a reasonable time after receiving written request for the information and on payment of a reasonable charge, shall furnish to an insured affected by a rate made by the rating organization or insurer, or to the insured's authorized representative, all pertinent information as to the rate. Pertinent information under this section does not include information that is a trade secret as determined by the director under section 2108(5) or 2406(6). Each rating organization and insurer that makes its own rates shall provide within this state reasonable means for a person aggrieved by the application of its rating system to be heard, in person or by his or her authorized representative, on his or her written request to review the manner in which the rating system has been applied in connection with the insurance afforded to him or her. If the rating organization or insurer fails to grant or reject the request within 30 days after it is made, the applicant may proceed in the same manner as if his or her application had been rejected. A party affected by the action of the rating organization or insurer on the request may appeal, within 30 days after written notice of the action, to the director, who, after a hearing held on not less than 10 days' written notice to the appellant and to the rating organization or insurer, may affirm or reverse the action. A person who requests a hearing before the director under this section may be represented at the hearing by an attorney. A person, other than an individual, that requests a hearing before the director under this section may also be represented by an officer or employee of that person. An individual who requests a hearing before the director under this section may also be represented by a relative of the individual.
MCL 500.2458