A trim panel attachable to a structural pillar of an automotive vehicle for covering an expandable side-curtain air bag. The trim panel can also be part of a vehicular pillar structure or a vehicle subassembly. The trim panel is composed of a unitary molded body having first and second body portions connected to each other. The first body portion is formed of a first material and the second body portion is formed of a second polymeric material that is more flexible than the first material. The second body portion is configured as a deflectable flap movable between a first position in overlying relationship with the side-curtain airbag in a non-deployed state and a second deflected position upon deployment of the side-curtain airbag.