Clearly, though, it´s not going to happen overnight. With the exception of DaimlerChrysler, which has built a plug-in prototype based on its Dodge Sprinter cargo van, automakers have been slow to get into the plug-in hybrid market. Aftermarket conversion kits will hit the streets for the first time later this year [see "Can I Plug In My Prius?" on page 84], tempting mileage-obsessed Prius owners like David K. Garman, undersecretary of the U.S. Department of Energy. "Like most Americans," he says, "I drive less than 40 miles a day, back and forth to work. If I´m able to drive in all-electric mode, I won´t need to use the gas tank. That, to me, is a game changer."