thats where the ballast plugs in. One on each headlamp. Headlamp auto-levelling is a totally different ballgame, the ecu for which is installed behind the glovebox. I've got all the bits for a xenon install, lamps, motors, bulbs and ballasts. I intend to mod them for manual levelling using the rheostat next to the headlamp switch. Thing is normal headlamps have 3 wires on the level motors and the xenon's have 4. Gotta find out the pin assignments first, before proceeding. Auto-levelling would cost about £400-500 to pickup the parts, loom and install yourself. Have a look at this link and see whats involved: furmanka.blogspot.com/