A vehicle floor tray is thermoformed from a polymer sheet of substantially uniform thickness. The tray has a central panel and at least first and second upstanding side panels joined to the central panel by curved transitions. Within a reservoir disposed in the central panel are plural, hollow treads/baffles. The treads/baffles have a width, in any horizontal direction, which is more than twice the substantially uniform thickness of the tray as thermoformed. The treads/baffles impede lateral motion, due to changes in vehicle speed or direction, of liquid collected in the reservoir.