Systems and methods achieve an optical effect of cabin enlargement of a passenger vehicle. The optical effect creates a visual impression of a higher cabin when viewed from the forward part of the cabin space looking aft, and a wider cabin space when viewed from the aft part of the cabin space looking forward. In preferred forms, a series of alternating interdigitated trapezoidal starboard and port headliner modules are disposed adjacent to the cabin headliner. The headliner modules are also preferably arcuately curved about a central elongate axis of the passenger cabin.