I have had my car for over 10 years and for many years NO PROblems except the normal tires, brakes and oil changes. Totally reliable car for about 10 years.
now its time for a new one but I don't really like the new body shape, so I'm waiting. I had very little problems with the car the first ten years but lately
had to purchase: new engine, radiator, muffler, coolant fluid recovery tank and sensor, freeze plugs, head gaskette, starter, lots of hoses and rear light bulbs, plugs and my mid console area is peeling terribly. The radio is gone out, trunk and hood hydraulics need replacing because neither will stay ajar. Worse, the mid console parts (mirrors control and knob, convertible top operation button and cigarette lighter for cell phone charging) all three knobs keep falling out and some stopped working totally. Let me add the heater and air conditioner do not work at ALL. My chrome rims need to be re-submerged in chrome because the tires keep leaking and must be sealed every six months. FYI- Stay away from Beverly HIlls Mercedes for service, biggest crooks on the planet.
Downtown Motors and Santa Monica is cool. Have not tried South Bay but heard horror stories about the service department.
Now I have a retired Mercedes Master Technician just come to the house and I get the parts at the dealer. Service cost about the same but NO lies. He only uses dealer parts which is totally appreciated..
I have always had my service A and B done whenever the indicator light came on AND I had an oil change, brakes, and tires twice a year despite I only did about 6L miles a year. So I think Mercedes last a good 10 years and then expect to buy a new one which is way better than a BMW, Ford or Toyota.
Practically, you should expect to spend $50,000 plus, and get a value of $5K/year for 10 years of stress free driving and comfort. I love my car but it is time to get another Mercedes. Hope they change the sLK body style soon.