A passive trailer system can be used efficiently for transportation tasks. However, backward motion control of a trailer system is difficult because it is an open loop unstable system. In our previous researches, we have shown that n passive trailers can be successfully controlled by an ommni-directional or a two-wheel-differential mobile robot. However, a passive trailer system pulled by a car is widely used in practical environments. Unlike mobile robots, a car-like mobile robot has nonholonomic constraints and limitation of the steering angle. In this paper, we tried to solve the backward motion control problem of the trailer system with a car by proposing two strategies. First, we proposed Driver Assistance System (DAS). By using the DAS, a driver can control the trailer system as a forward motion control instead of a backward motion control directly. A driver only secure the rear view of the last passive trailer, and select the control input to drive the last passive trailer. The DAS converts the control input of a driver into the velocity and a steering angle of a car by inverse kinematics. The DAS can be achieved combining several electronic devices which are recently embedded in a car in general. Second, we proposed a kinematic configuration which is connecting a passive trailer to the front bumper of a car for increasing the feasible region of backward motion control. Performances of the proposed control strategy and the kinematic configuration are verified by theoretical verifications and experimental results.