A 2008 Mercedes C300 battery location is under the hood of the car, beneath your cabin’s air housing on the passenger side of your vehicle. In order to access it, you will need to unclip the plastic cover.
Your C300’s battery will be located closer to where your front shield meets the hood of the car. If your headlights are flickering, we’d suggest you check for signs of visible corrosion or leaks. And, if the problem persists, you may need to get your vehicle checked out by a professional.