320.6992  Application.--This act shall apply to all presently existing or hereafter established systems of distribution of motor vehicles in this state, except to the extent that such application would impair valid contractual agreements in violation of the State Constitution or Federal Constitution. The provisions of this act shall not apply to any judicial or administrative proceeding pending as of October 1, 1988. All agreements renewed or entered into subsequent to October 1, 1988, shall be governed hereby.