On April 2010 a group of cyclists dumped 13 gallons of paint on the road at Rosenthaler Platz in Berlin. In just a few seconds they poured water-soluble paint in front of the cars waiting for the green light.While driving thought the car wheels (in)voluntarily served as brushes spreading the paint throughout the intersection .
The result is a nice piece of guerilla art, a little surprise, color spread in the most boring part of public space and Lego looking cars with yellow and purple wheels!
Shall we say too bad that the paint was not permanent or it is not socially considerate?
pictures taken from here