I'm considering buying either an '06 E320 CDI or an '07 E320 CDI. The '06 has the inline 6 and the '07 the new Bluetec V-6. I would certainly appreciate any comments regarding the differences in mileage/smoothness/reliability/experiences between these two engines. Also, does the '06 CDI have the 7 speed automatic transmission? I believe the '07 CDI comes with the 7 speed trans. THANKS for all your input!!!