A car seat is configured to rest on a seat of a vehicle and to support a child, and the car seat has a shell with a front side and a rear side and a seating surface on the front side. A first contact surface is defined on a part of the car seat facing generally opposite the seating surface. The first contact surface is oriented to support the car seat with the seating surface at a first seat incline. One or more adapter bodies are carried on the car seat and movable between a stowed position and a deployed position. The one or more adapter bodies each define a second contact surface. With the adapter bodies in the stowed position, the first contact surface is exposed to rest on the vehicle seat. With the adapter bodies in the deployed position, the one or more second contact surfaces are exposed and oriented to support the car seat with the seating surface at a second seat incline different than the first seat incline.