A liftgate is provided with a modular sensor housing that spans a substantial portion of the width of the liftgate. The sensor housing has a plurality of rearward-facing apertures adapted to permit the cameras and/or proximity sensors from the vehicle to “see” through the housing. The sensor housing incorporates a plurality of sensor mounting brackets specifically adapted to the particular configuration of the vehicle sensors. The modular sensor housing enables a liftgate to be installed without disabling the rearview camera and proximity sensors.