The Jaguar F-type coupé, expected to launch next year, has again been spotted testing on the M5 motorway showing its retractable rear wing. The car had previously been seen testing alongside the standard convertible.

The F-type coupé is expected to be powered by the same range of V6, V6 S and V8 engines offered on the drop-top, as well as be the initial basis for more extreme versions of the car, ranging from S and RS models through to an extreme 600bhp Jaguar F-type RS-GT road racer.

A hotter, 'R' version of the F-type coupe is also in development and has already been spotted testing.

Comparing the rooflines of the two models, the coupe has an obviously larger, sloping rear end. It is unknown whether Jaguar will change the design of the coupe's rear bumper to make it an overall larger model than the standard roadster.

Recent spy shots have shown the F-type coupé to be almost identical to the original C-X16 concept, which launched the idea of a new Jaguar sports car, and the standard F-type roadster. The shift to on-road testing indicates that the car's launch would typically be 12 months away, towards the end of 2014.

Jaguar insiders have subsequently admitted that the CX1-6 concept car was designed after the production versions of the F-type were completed, as they were conscious of not producing a concept car that was more flamboyant than the production version. The unusual decision to launch the roadster first was taken because it was perceived to have a large market and deliver a better image for the firm's halo model.