Michigan Compiled Laws, Chapter 257. Motor Vehicles § 257.707e

Sec. 707e. (1) Test instrumentation and procedures used for implementation and enforcement of sections 707a to 707d  1 shall substantially conform with applicable standards and recommended practices established by the society of automotive engineers, inc., and the American national standards institute, inc., for the measurement of motor vehicle sound levels. Rules establishing these test procedures shall be promulgated by the department of state highways and transportation. The rules may provide for measurement at other than the distance specified in section 707c,  2 provided that the decibel limits applied at the other distances are adjusted accordingly, to meet the standards in section 707c. The rules shall be promulgated pursuant to Act No. 306 of the Public Acts of 1969, as amended, being sections 24.201 to 24.315 of the Michigan Compiled Laws.

(2) This act occupies the whole field of vehicle noise regulation. A city, county, village, or township shall not adopt or enforce vehicle noise rules unless the rules are identical to the requirements of this act.