1. Locate the air filter housing. It is usually placed in the engine compartment, at the top of the engine. In the Mercedes-Benz C300, the airbox cover is in the back, on the left.
2. Unfasten the clips holding the airbox cover. There are two of them, they can be found on both sides of the airbox. Press the tabs on the clips and lift them up.
3. Lift up the air box top cover. Be careful not to drop it.
4. Remove the air filter. It is a rectangular, foam, slightly-curved piece. Lift the air filter element straight up and out.
5. Inspect the air filter and, if it is visibly dirty or clogged, replace it with a new one. It's advisable to replace the air filter every 15,000 to 30,000 kilometers (or 10,000 to 20,000 miles), according to the recommendations in the vehicle's owner manual.
6. Place the new air filter in the air filter housing. Make sure it sits correctly and is level. Put it in the opposite way you removed it.
7. Secure the airbox cover. Snap it back into place by securing it with the tabs. Press on them until you hear a clicking sound.
8. Close the hood of your car.
Remember to always refer to your vehicle's owner manual for any specific instructions or recommendations related to your car's airbox and air filter replacement process.
