According to Zack Woods in his article "Big Fans of the Small (Airstream) Westfalia" (Spring 2011 issue of Airstream Life), "“By most estimates, there were 192
Airstream Sprinter Westfalias imported into the United States [for only two years, 2005-2006], all based on the Mercedes Sprinter diesel van… The number of owners is small, but their passion for these very efficient and effectively designed campers is huge.”
If you like the concept, you might like to check out the
Airstream Interstate and Airstream Avenue and read the article, "
Fans of the Airstream Interstate".