Purchasers of General Motors Corp. (GM) (plaintiff) cars paid sales tax under the General Sales Tax Act (GTA) that was remitted to the Michigan Department of Treasury (defendant). Purchasers received a limited warranty as part of their payment price. The treasury did not apply tax under the Use Tax Act (UTA) to replacement parts provided under the warranty, because the purchasers paid for the right to such parts—and thus paid GTA tax on such parts—as part of the purchase price. The UTA exempted from tax “tangible personal property [that] is transferred for consideration.” GM also offered to purchasers a goodwill adjustment policy, under which it had the discretion to replace certain parts even after expiration of the warranty. Although such replacement was not guaranteed, purchasers were told to contact the dealer if problems arose after the warranty period, with the goal of resolving the issue to the “customer’s satisfaction.” GM included this policy in writing in its warranty manual provided at the time of sale. The treasury began taxing replacement parts provided under the goodwill adjustment. GM appealed the treasurer’s decision to the court of claims, arguing that, like warranty parts, the treasury could not, under the UTA, tax replacement parts provided under the goodwill adjustment policy, because they were taxed under the GTA at the time of sale. The court of claims affirmed the ruling in favor of the treasury, as did the court of appeals. The Michigan Supreme Court granted leave to appeal.