很簡單,RWD cars 都有frame。不要小看這個玩意兒,車禍時事關重大。除了側麵衝撞 unibody car can be cut into pieces, in head-on accidents, unibody can be deformed and driver can be hopelessly stuck inside.
You can think of race cars. Recently I saw a scene that a car was hit and lost control in the middle of race tracks, frogged and flipped on to fence then bounced back to mid court. Amazingly the driver walked out unharmed. Why could that be? It's about frame - not only under frame, but also upper frame - many metal bars were welded into a nest to protect the driver inside. Aren't you convinced?