A few nice bi injection molding method images I found:
Nomination 54 – Overall performance & Customization – Hidden Dome Lamp
Image by spe.automotive
HIDDEN DOME LAMP
•OEM Make & Model: Ford Motor Co. 2013MY Lincoln® MKZ® luxuary sedan
•Tier Supplier/Processor: Grupo Antolin / Pacfic Insight
•Material Supplier / Toolmaker: Styron LLC / Hong Kong Mould Manufacturing of Canada Ltd.
•Material / Method: Pulse® 2000EZ Computer/ABS / a number of
•Description: In order to give a "surprise & delight" element, boost the sense of interior spaciousness, and achieve greatest-in-class rear-seat lighting, hidden dome lamp was integrated into the headliner behind the fabric and outfitted with capacitive switch technology so the lights can be turned off/on with the wave of a hand. A bi-laminate (fabric/foam) headliner enables for greater light transmissibility. The LED lamp’s housing is injection molded with Computer/ABS in a two-cavity injection tool that enables a clear window to be overmolded onto the housing for the duration of a 65 sec cycle.