A seat member providing a support structure of a seat in a vehicle is integrally formed of a synthetic resin material and includes a seat base portion and wing or flap portions. The seat base portion is formed with a plurality of openings and is partly thinner than the remainder to provide desired resiliency....http://www.google.sh/patents/US4368917?utm_source=gb-gplus-sharePatent US4368917 - Vehicle seat member integrally formed of synthetic resin material
