Getting your vehicle cleaned at the car wash uses less water than hosing it down at home and less gas than driving it into a river. Combat grime efficiently with today's Groupon: for $7, you get three exterior Cash and Dash car washes at Magnum Car Wash & Lube in Winston-Salem (a $15 value).

Sloppy jalopies roll out of Magnum Car Wash & Lube, a full-service oil-change and detailing outfit, as gleaming road warriors. The Cash and Dash car wash polishes autos from grill to trunk in five sudsy minutes, making it an ideal service for commuters on the go and a fatal mistake for naive robots. Motorists relax in their car's cockpit as cleaners swiftly strip car shells and undercarriages of caked-up, corrosive road grime and imprison shine with a coating of sealer wax.