In Williams v. Vermont, 472 U.S. 14 (1985), the Court addressed Vermont's practice of charging a use tax on the registration of motor vehicles by "registrants who purchased their cars out-of-state when not Vermont residents . . . regardless of whether they already paid a sales tax in another jurisdiction on the same car." 472 U.S. at 19. At the same time, a Vermont resident "enjoyed a credit for any sales tax paid to a reciprocating State, even if he registered and used the car there before registering the car in Vermont." Id. at 21. The Court struck down, as a violation of the Equal Protection Clause of the U.S. Constitution, the practice of imposing the use tax only on those who were not Vermont residents at the time they purchased the vehicle and paid sales taxes to the state of purchase. Id. at 22.