Jaguar’s long-awaited ‘new E-type’ is now just 18 months away from a public unveiling. After two abortive attempts to replace the iconic E-type, Jaguar insiders say that this all-aluminium car will finally step confidently into the gap left by its historic predecessor.

One suggestion is that the production car will be launched at the Detroit motor show in January 2013, some 50 years after the introduction of the ‘Lightweight E-type’, which competed at the Sebring 12 Hours and Le Mans in 1963.

These scoop shots taken near Jaguar’s Whiteley research and development centre reveal an early engineering prototype based on the current XK cabriolet.

See the first scoop pics of the new Jaguar 'E-type'

The new E-type is expected to come in both cabrio and coupé versions and most models will be powered by a V6 petrol engine. A V8 version is expected further into the future. There’s no news on whether a V6 diesel engine will be made available, though the new architecture is expected to be capable of accommodating the engine, unlike today’s XK.

Although the original aim was to build a roadster that competed directly with the Porsche Boxster, the final car is both wider and longer than the Porsche. The new E-Type will be based on the same basic aluminium structure as the next-generation XK. Both cars will be built at Castle Bromwich, near Birmingham.

Creating two cars of a different size out of the same basic architecture has provided a significant headache for Jaguar engineers, but insiders say that the final car will be nearly the same width as today’s XK but some 250mm shorter, at around 4.55m long.

Read Autocar's Jaguar XKR-S first drive review

As can be seen in these scoops shots, most of the length reduction has taken place between the trailing edge of the driver’s door and the rear wheel arch. However, this short-tail, long-nose, stance is a direct reflection of the proportions of the original E-Type.

The grille shape and headlamp layout is, though, expected to be closer to the CX-75 supercar concept.

American demand for a new-generation XKE (as the E-type was known in that market) is expected to be significant, especially among affluent female buyers who make up a significant proportion of Jaguar’s Stateside customer base.

Hilton Holloway Read more on the new Jaguar X-type saloon and estate

See all the latest Jaguar reviews, news and video