Michigan Compiled Laws, Chapter 257. Motor Vehicles § 257.1337

Sec. 37. (1) If a mechanic or mechanic trainee is employed by, or enters into a contract with, a motor vehicle repair facility, that mechanic or mechanic trainee for the purposes of a civil action brought pursuant to this act shall be considered to be an agent of the motor vehicle repair facility and the methods, acts, and practices of the mechanic or mechanic trainee shall be construed as the methods, acts, and practices of the motor vehicle repair facility.

(2) A person who directly or indirectly controls a motor vehicle repair facility or its employees, as well as a general partner, officer, or director of the facility shall be jointly and severally liable among themselves for a violation of this act, unless that person can demonstrate that he did not know, and in the exercise of reasonable care could not have known, of the existence of the facts by reason of which the violation occurred. There is a right to contribution as in cases of contract among persons so liable.