I just picked up a CPO 2007 E320 Bluetec. This is my 3rd Mercedes-Benz diesel ('74 240D 4 speed - 440K miles on it when the engine died due to loss of oil, and an '84 300D turbodiesel - sold at 337K miles and it's still running strong, from what I hear. This one is by far the best of them - I cannot imagine a car needing anything more than this car offers - quiet, fast, excellent fuel economy, beautiful build quality - it's all there. Only concern I had was repair cost, so I extneded the CPO warranty by two more years, to get me through 2013 - it was certainly cheap insurance, considering the labor rates and parts costs if something does go wrong out of warranty.
Mercedes-Benz build quality - this car is solid, tight and incredibly well- built. I love (and have missed) that Mercedes vault-like 'thunk' when closing the doors, hood and trunk. Fuel economy and performance is excellent - 28mpg around town - no road trips yet, but can't wait!
Tall drivers may find entry a bit odd at first. I've noticed I tend to brush against the B-pillar when getting into the car. Bluetooth module should have been standard in this car, n a $500 accessory, and what is up with a $200 i- Pod connector cable? Power lumbar support adjustment would be nice