The Dip stick For The Engine Oil has a Handle (BLUE) With a Hole In it. To Check the Engine Oil Level..It Can Also be Used for the Topsider Oil Change!

The Plug You are looking at (Black) Cap/Plug at the Pass side of the Engine Compartment is for the Auto transmission..it has a Tamper proof seal that must be broken to Inspect The Trans Fluid IF You have the Factory Mercedes Dip Stick!