Mich. Comp. Laws § 257.972

Sec. 2. From and after January 1, 1960, in lieu of the specific weight taxes authorized by section 801 of Act No. 300 of the Public Acts of 1949, as amended, being section 257.801 of the Michigan Compiled Laws, city, intercity, and suburban bus operators and public transportation operators shall pay the sum of $25.00 per vehicle for each vehicle operated as specified in section 1, which shall exempt the vehicle from all other taxation except the fees and taxes required by Act No. 254 of the Public Acts of 1933, as amended, being sections 475.1 to 479.49 of the Michigan Compiled Laws.