A fan shroud for an internal combustion engine includes a snap-on detachable overflow bottle. The fan shroud has a fan opening and a unitary bottle mount with a deflectable bottle clip with a latch end that engages a groove in the overflow bottle. The mount includes an opposite side with an inwardly directed locking surface that engages a recess in a side face of the overflow bottle. The overflow bottle is held upright and secured to the fan shroud by snapping it into the bottle mount.