A vehicle includes a vehicle seat assembly having a seatback member and a lower seat member. The lower seat member has a generally horizontal and upwardly-facing seating surface. The seatback member has a cushion portion and is selectively rotatable between an upright position in which the cushion portion is adjacent the wall and a lowered position in which the cushion portion extends farther forward than the seating surface. The seatback member functions to support the back or head of an occupant (when the seatback member is in the upright position) or as an extension to the lower seat member to provide additional fore/aft support to a child seat.