Me. Rev. Stat. tit. 10, § 1181

In connection with a sale of a motor vehicle or vehicles to the State or to any political subdivision of the State, a manufacturer, distributor, wholesaler or corporate affiliate may not offer any discounts, refunds or any other similar type of inducement to any dealer without making the same offer or offers to all other of its dealers within the relevant market area, and if such inducements are made, the manufacturer, distributor or wholesaler shall give simultaneous notice of the inducements to all of its dealers within the relevant market area.