Mich. Comp. Laws § 124.354

Sec. 4. The authority shall be a body corporate with power to sue and be sued in any court of this state. It shall possess all the powers necessary to carry out the purposes of its incorporation and all things incident thereto. The authority by contract may employ a management firm, either corporate or otherwise, to actually operate the mass transportation system, under the supervision of the authority. The enumeration of powers of this act shall not be construed as a limitation on such general powers.