My cousin is a mechanic for a dodge dealer. The Liberty Diesel was backordered for so long due to parts issues. The Mercedes Diesel had nothing but problems with US fuel and they had most of the ones their dealership sold sitting in the service department for long periods of time waiting for parts. Thats why they canned the option.
They really should have revised the Cummins 4 cyl engines when they did the 6cyl in 2003 and started sicking those in everything.