These plugs came with the car's original PDA kit. Its a package that comes in the car direct from factory and the dealer is supposed to install the items in the kit. Things like the 2 front plastic grilles below the bumper, the licence plate holders, wiper blades, floor mats and these 4 rubber plugs. Most dealers did not install these plugs, from what I gather from other posters. Mine were not installed, I found them in the glovebox, so installed them myself.

They are called "wheel arch liner plugs" if you need to tell your dealer what they are.