I bought a pristine 2005 used C240 4Matic in 2007 and have been extremely thrilled by the car and service from MB. Drives great, interior is the best in its class and I think the exterior is very iconic. The 4matic has been a great feature for the Snow here in Rochester, NY. The car is extremely solid and you feel very safe no matter your driving conditions.
I have always enjoyed the indash LCD thats gives you complete control of your car including check your oil level if desired. The feel of this car is great and handles great in the snow.
I think fuel economy is always a thing to be improved in this day and age. Also I wiring for a phone system can be expensive though new 2008 C Classes have phone features standard.