A vehicle roof assembly includes a roof panel having longitudinal edges, each of which define a rim, structural bars disposed within and running along at least a portion of the rims, and frame rails running along at least a portion of each of the longitudinal edges. The rims abut the frame rails, and the structural bars are fixedly attached to the frame rails. Preferably, the rims are glued to the frame rails. The structural bars each include a web portion disposed between a contact surface abutting the roof panel, and a contact surface abutting the frame rails. Top-carriers including top-carrier cross braces are selectively attachable to the roof panel, and the structural bar. A roof liner is attached to a bottom surface of the roof panel, and an intermediate layer of plastic foam is disposed between the roof liner and the roof panel.