Mich. Comp. Laws § 257.707d: Violations; penalties; liability; prima facie evidence.

Sec. 707d.

A person who violates section 707c(2), (4), or (6) is guilty of a misdemeanor punishable by a fine of $100.00.

A person who violates section 707b or 707c(1), (3), or (5) is responsible for a civil infraction.

A person who, at the time of installation, knowingly installs a muffler or exhaust system which exceeds the decibel limits of this act shall be liable to the person who receives a citation for violation of 707c for the amount of not less than $100.00, plus reasonable attorney fees and court costs.

If it is shown that the noise level of a motor vehicle is in excess of the DBA levels established in this act, that evidence shall be prima facie evidence that the motor vehicle was producing excessive noise in violation of this act.

A violation of section 707c(4) or (6) by a dealer licensed under this act is prima facie evidence of a fraudulent act under section 249.