Vehicle seat with integrated booster seat and with interchangeable modules

A vehicle seat having an integrated booster seat in which a child booster seat cushion is disposed within a cavity in the seat back and is rotatable to a forward extending use position spaced above the seat cushion providing a raised booster seat cushion for a child to elevate the child to a position in which an adult restraint system can be used with the child. The seat back has a movable panel which covers the cavity in the seat back in which the booster seat cushion is stored. Once the booster seat cushion has been moved to its use position, the panel is returned to its closed position whereby the panel forms the seat back surface for both an adult and a child. The booster seat can be provided in a form of a removable module which can be removed from the seat back and replaced with another module containing unique features such as an integral child seat or an armrest module.