At the hometown coming-out party for the Mercedes-Benz R350 people hauler--which had its international debut at the New York show--Mercedes brought out a short-wheelbase variant as well as a production-ready "concept" AMG, the R63 AMG.
The short-wheelbase R-class trims 9.25 inches from the length but still manages to cram in a third row of seats, maintaining six-passenger seating, albeit under very compromised conditions compared to the larger R. The abbreviated R-class is for the European market only--don't expect to see it stateside, except when it's rolling out of the factory in Vance, Alabama, where it's built alongside the larger R-class and the M-class.