Painted graffiti has a pretty bad rap for adding more messes to a city, but reverse graffiti is artful and actually helps to clean up. This campaign from Nissan makes use of dirty walls in London and Hamburg and shows Moose, a reverse graffiti artist, using a pressure washer, stencils and wire brushes to create beautiful, but subtle artwork on city structures. If you're wondering, a lot of the time, the dirt on the walls actually comes from vehicle exhaust.
The reverse graffiti artwork features an artful interpretation of the city, complete with buildings, bodies of water and cars that help to keep the city clean. The artworks are also tagged with #ZeroEmission, which is tied into the promotion of Nissan's LEAF, which is a 100% electric vehicle that also does its part to keep cities clean.