A four-door lifeguard pickup, finished in white with orange side stripes and rescue equipment on its roof and bed, is due to appear in Grand Theft Auto VI. It shows up twice in the first trailer, driving up the shoreline in the establishing shot and parked on Vice Beach hitched to a boat trailer, and its design seems to be based on the Ford Explorer Sport Trac.
Vehicle data via GTA Wiki (Fandom), CC BY-SA 3.0.