In Independence Twp v. Eghigian, 161 Mich App 110, 112-113; 409 NW2d 743 (1987), the defendants parked a 1967 Ford dump truck weighing 17,000 pounds in their driveway. In 1975, the plaintiff limited commercial parking in residential areas to trucks weighing less than 10,000 pounds. Following the effective date of the ordinance, the defendants sold their truck and replaced it with a dump truck weighing 27,000 pounds. The Court held that the critical point for vesting the defendants' nonconforming use was the time of enactment of the zoning ordinance. Because the defendants' nonconforming use was for a 1967 Ford dump truck, any replacement vehicles would have to be compared to that standard to determine whether there was an unlawful extension of defendants' vested use. Independence Twp, supra at 118.