My coach is a 2007 and does not have a DPF, chassis may well have been produced in 2006. It is built on a Spartan K2, Cummins ISM 450 that is software upgradeable to 500 with 1550 lb ft of torque also has comfort steer. Based on my research and my needs, 2007 was the absolute sweet spot. The 2008's have frameless windows, but that is about the only difference besides less depreciation. Mine was a private sale, I had the coach in dependently inspected.