I did a lot of research and realized that the I-6 CDI motor was one for the ages. Iron block, naturally balanced, dependable and durable. I had to purchase a "pre-owned" 2006 since I live in the great state of California. I arrived and I could not be happier. My father has owned many MB cars over the years, this CDI is as close to a perfect car as he and I can imagine. It is the perfect size, seats 5, it has outstanding acceleration and curising speed capability and I got 35 MPG over a 226 mile trip (including several acceleration runs). On that 226 mile trip I used just a smidge over 1/4 of the tank. The range left is 400 miles. I am looking forward to this car for years to come.
I love the smooth and effortless engine, the acceleration and especially the MPG. The ride is solid with no wind noise whatsoever (.27 cd!). I simply laugh at the hybrids who will face major $$ when their batteries need to be replaced. I will be long gone on my way to 300k miles of MB driving.
The only minor thing I can think of is that the accelerator takes some getting used to. The electronic throttle control is not like the old cable throttle and there is a learning curve for the driver.