The S45R and S53R are the popular underfloor engined 1977 versions of the S45 range introduced in 1964. This restyled version was continued by Renault until 1988, when it was face-lifted again. The rear-end shown is typical for the S45R and S53R. The S105R, shown separately, can be distinguished by a different rear end. The S53R may have the destination blind of the S105. The S45R is the shorter version, the S53R the longer one. The difference can be seen in the window bays on the left hand side of the vehicle. The S45 has a narrow first window, about 1/3 normal size, and a narrow sixth window, about 1/2 normal size. The S53 has a 1/2 size first window and a full size sixth window (this is excluding the driver window). On the left hand side of the vehicle the front door of the S45R is very close to the wheel arch, while in the S53R there is some 15 cm space between the door and the front wheel arch. The door lay-out on both models varies, though only the S53 can have centre door.