Those plugs are what would connect to the back of the HB3 & 4 bulbs used in the stock headlight units. But as KASPar says, they aren't stock. If you look for replacements, make sure they're from the same spec car as your own, otherwise they may be missing the integrated sidelights (which are positioned separately in the bumper on widebodies and facelifts). Or vice versa.
If you care for my opinion, it would probably be a simpler solution to keep the headlight units and replace the bulb or ballast (or just fit a new HID kit). They do work well.