An interior trim structure covers a stowed side curtain airbag and allows deployment of the side curtain airbag through an interface joint to a position along a sidewall of a passenger compartment adjacent a rear seat location of a two-door coupe style vehicle. A center pillar trim piece and a rear pillar trim piece can be assembled to one another with at least one projection releasably interlocking with a corresponding aperture formed along adjacent edges of the trim pieces. Each projection is located in a complementary position with respect to a corresponding aperture formed along the adjacent edge to temporarily secure an interface joint defined between first and second edges when in an abutting relationship with respect to one another in a closed position. The interface joint defines an openable passage along the first and second abutting edges allowing deployment of a side curtain airbag through the interface joint.