Ford sales analyst George Pipas said that a "significant" portion of the 23,800 April Explorer sales were dumped on rental companies. Even with the rental boost, Explorer sales were down almost 15 percent for the month. Fleet sales equal trouble with resale values and leasing profits if the vehicle's value drops more than what was predicted when the lease originated. We're sure Ford would love to convert one of the Explorer plants to build Mustangs. The Mustang sold almost 20,000 units in April, the most since 1980 when buyers were ecstatic that the Mustang II was history.