The application provides non-circular steering wheel designs and steering wheel-mounted airbag housings, cushions, and modules for use in vehicles using non-circular steering wheels. The airbag housings and modules of the invention provide supplemental reaction surfaces to support an airbag cushion mounted on a non-circular steering wheel. Airbag cushions of the invention utilize the steering wheel, steering column or steering wheel shroud as a partial reaction surface to support an airbag cushion.