Abstract: A lamp unit (10) for being removable positioned within the rear opening (11) of an automobile headlight reflector (13). The unit (10) includes a plastic holder (19), an electric (e.g., tungsten halogen) lamp (30) having a filament structure (42) contained within the envelope (33) thereof, a clamp member (46) secured to the lamp's press-sealed end portion (47), and an insert member (48) located within a cavity (21) of the holder (19). The clamp member (46) includes a pair of skirt portions (57) which frictional engage and are thereafter secured (e.g., welded) to the innermost surface of an upstanding portion (61) of the insert member (48), thus facilitating alignment and positioning of the lamp (30) relative to the holder (19). The insert member (48) is only partly inserted within the holder's cavity (21) to effect the defined securement and is thereafter attached to the holder.