 In the 1970's, if your car reached 50,00 miles it was time to get rid of it.  At that time you could be assured that major problems would begin and continue.  The 2010 C300 Mercedes-Benz had me reliving the 1970's.  After 60,000 miles the car fell apart.I purchased a 2010 C300 in 2011.  The car was a certified used car, mileage 9,403, from a local dealer in Pittsburgh and all of the service done on this car was performed at the dealership where it was purchased.  The first 30,00 miles were OK, but since then I have had a major issue every 5,000 miles and things really turned bad after 60,000 miles.  I have had two problems with the key system.  One issue was covered under warranty and the second problem cost $1,000.  The second problem with the key system had the car totally locked in park.  Mileage 67,000. I had the car towed to a dealer.  The car was locked in park and the car had to be dragged on to a flatbed truck, none of the wheels would rotate, and hauled to the dealer.  This happened in Oct. 2015 and cost $800. The dealer technicians are competent, but the service is very expensive.  If your trip for service costs less than $1,000 consider your self lucky.In Jan. 2016 the heater/AC blower was replaced for $600; mileage 70,300, and the car was just serviced at 69,945 miles for the annual Pennsylvania state inspection.  In Mar. 2016 the right headlight went out and required dealer service to fix a wiring problem.  On May 2, 2016 the left axle broke; mileage 72,137.  For the second time the car was on flatbed back to the dealer.  I was pulling out into traffic when the axle broke and the car was immobile.  The cost this time was $1800.  After the repair I drove the car home and it sat in the driveway until I purchase a new car. I would not drive the car anywhere out of fear it would breakdown.   I am no longer the owner of a stylish, expensive, and UNRELIABLE Mercedes-Benz.  If you still insist on buying a Benz, BUY an extended warranty and hope for the best.