Child car seat

A fully-dismantleable child car seat 110, (10 , see figure 1a) comprising a multi-part seat body (12) having a plurality of modular releasably engagable support elements stowable into a collapsed compact arrangement when not in use, wherein one of the support elements 128, (28) is capable of housing the other support elements in the collapsed compact arrangement. Preferably the seat has engagement means for coupling to an existing restraint system (1000) of a vehicle; a gluteal support element, which is a squab portion 18 having a recess 34 for housing other mutually stackable modular support elements in the collapsed arrangement; said support elements include engagable interface portions comprising co-operable spring pin locators (174, 182, figure 4) and receivers (172, 178); the collapsed arrangement is substantially cuboidal with a reduction in volumetric envelope of more than 75%. A method of stowing such a car seat is also provided.