For safety and operability of drivers while operating a vehicle, it is very important to obtain a wide field of vision. However, the space available for setting up windows is limited. Therefore, we propose a "transparent cockpit," in which the image of a blind spot is displayed on the inner wall of the vehicle using a retro-reflective projection technology. In this system, the internal components of the vehicle, such as the doors and floor, are virtually transparent, and the blind spot is clearly visible, as observed from a window. In this paper, we describe the implementation of a prototype of the proposed system and demonstrate its effectiveness by an evaluation experiment.