From the people that gave you spray-on mud...

If you own a Kelvinbridge tractor or lust after one:

A special report from the Sierra Club about the impact of sports utility vehicles on the environment. Includes discussion about the pollution created by SUVs, the role of the United States as one of the top polluting nations, and the relationship between dependence on oil and national security.

http://www.sierraclub.org/globalwarming/SUVreport/

Spray-on mud?
http://www.sprayonmud.com/
Spray-on mud.

Source: Librarians' Index to the Internet