Vehicles equipped with optional Xenon headlights utilize a special high voltage bulb and control unit for the low beam headlights, while high beam bulbs remain conventional Halogens. For the driver's side headlight, the air filter housing must be partially removed, and for the passenger side, the windshield washer reservoir needs to be partially removed. In 2004-2006 (pre-LCi) vehicles, while working in the engine compartment behind the headlight, unlock the catch and remove the cover. Rotate the ignition unit for the Xenon headlight approximately 30° counter-clockwise to detach it, which will automatically release the Xenon bulb plug connection. Feed the ignition unit out of the headlight opening and remove it from the back of the headlight housing. Rotate the bulb retaining collar counter-clockwise, pull the Xenon bulb out of the reflector, and replace it without touching the bulb surface with bare fingers, as grease can cause premature failure. Installation is the reverse of removal, ensuring the bulb is fully seated in the headlight. In 2007-2010 (LCi) vehicles, the Xenon ignition unit and bulb are an assembly that should not be separated. While working in the engine compartment behind the headlight, unlock the catch and remove the cover. Disconnect the electrical connector from the ignition unit and bulb assembly, unhook the wire spring clips to release the assembly, and remove it from the headlight housing without touching the bulb surface. Installation is the reverse of removal, ensuring the ignition unit and bulb assembly is fully seated in the headlight.