Inbuilt (tilt-vent-slide) sunroof systems have a panel which slides between the metal roof and interior headliner, requiring some loss of headroom but providing a full opening in the roof. All inbuilts slide inside the roof, while some also include a rear venting feature (see pop-up). Historically, inbuilts were a metal sunroof panel painted to match the vehicle roof, but now most are glass-panel systems with sliding sunshades (typically referred to as moonroofs).