The ELR is Cadillac's first-ever plug-in hybrid (PHEV), a dramatically styled coupe that shares its high-tech underpinnings with the Chevrolet Volt. To go with its big price tag, the ELR gets a high-tech interior with luxurious finishes and handy touches, and a chassis whose ride quality equals that of any of Cadillac model. Of course, the ELR's biggest selling point is its fuel economy: many daily drivers will get away with using no gasoline at all.