Art car recent years the festival has been forced to limit the number of vehicles on the playa. As such they have restricted the vehicles that are licensed to what they are now calling "mutant vehicles". There has been some confusion within the Burning Man and Art Car communities over these two terms, with some believing the terms are simply synonyms. According to art car artist and Art Car Fest organizer Philo Northrup, art cars are "street-legal vehicles that have been permanently transformed into mobile sculptures". According to the Burning Man DMV ("Department of Mutant Vehicles"), Mutant Vehicles are "'art on wheels':
Anaglyph 3D anaglyphic photo image. A red filter lens over the left eye allows graduations of red to cyan from within the anaglyph to be perceived as graduations of bright to dark. The cyan (blue/green) filter over the right eye conversely allows graduations of cyan to red from within the anaglyph to be perceived as graduations of bright to dark. Red and cyan colour fringes in the anaglyph display represent the red and cyan colour channels of the parallax-displaced left and right images. The viewing filters each cancel out opposing colored areas, including graduations of less pure opposing colored areas, to each