This kind of thing really appeals to me: the scale, the careful planning and execution of the team, the inadvertent participation of the drivers, the chanciness of the aesthetic outcome (via Honestly WTF).
I am not a big watcher of televised parades and spectacles, but for some reason I did watch parts of the opening ceremonies of the Beijing Olympics, which included a project in sympathy with this one, I believe during the parade of nations. The athletes walked through some kind of colored powder then onto a white surface, creating an ombre effect. My REALLY cursory image search revealed nothing of this (did I imagine it?) and my search for footage on YouTube also came up dry. It seems that NBC yanked everything related to the broadcast. Bastards!