How many ATV / Personal off-road vehicles (not to include motorcycles)
are in use in the U.S?  How many vehicles (units) sold each year in
2000-2004?  What are projected sales for 2004 onward?  Are detail by
vehicle type/class, brand, or geography appreciated.

Background:
In Aug. 2002 Google Answers was asked "What was the size (in dollars)
of the U.S. market for All-Terrain Vehicles in 2001?"
Answer - http://answers.google.com/answers/threadview?id=6088