I largely disagree with the previous post. What type of driving are we talking here - droning along the freeway, or stop & go, flat ground or climbing mountains? The car is expected to run warmer in some situations than others, and near 100F with the a/c blasting will definately result in higher engine temperatures.

That said, it's running hotter than it should. I respectfully disagree with the previous poster; you're not about to damage the engine. But you do have a problem in the formative stages here.

I would not replace the radiator right away, that's an expensive option. Start with the simple stuff first, and work your way up the cost/complexity ladder. First, make sure the a/c condensor & radiator are clean and free of debris. A surprising amount of crud can build up in the narrow space between them, resulting in substantially blocked airflow. Give it a good inspection, clean it out with a hose, consider pulling the radiator to get a thorough cleaning.

Second, suggest you flush the cooling system. MB recommends a citric acid flush. You can find lots of information here using the search function. Refill using the correct MB or Zerex G-05 coolant. Changing the coolant won't make it run at a lower temperature, but it is the formula MB recommends for long term protection against corrosion and other nasties.

Let us know how it goes. There are a bunch of other possibilities, such as the radiator, electric fans, engine driven fan clutch, thermostat, water pump, etc.

- JimY