Cadillac’s rear-wheel drive rival for the BMW 7 series and Mercedes-Benz S-Class will go into production in the fourth quarter of 2015 at the Detroit-Hamtramck assembly plant, General Motors has confirmed.

Mark Reuss, GM’s head of product development, told reporters recently in Detroit that Cadillac needed to be in the top car segment if it was to be taken seriously as a luxury carmaker.

The new – as yet unnamed - model will sit above the XTS saloon and has been confirmed a year after Cadillac unveiled its Elmiraj concept.

GM said in a statement this new model, an addition to the Cadillac range, is part of a previously announced US$384m investment in the facility on Detroit’s east side. Tools and equipment unique to the Cadillac model were installed recently.

"The objective for this upcoming model is to lift the Cadillac range by entering the elite class of top-level luxury cars," said Cadillac president Johan de Nysschen. "Currently in development, this new rear wheel drive-oriented sedan uses completely new, custom-designed materials on a unique vehicle architecture.

"In addition to new technology in the car itself, we are instituting innovative manufacturing techniques to assemble it with the precision deserving of a luxury make."

The Detroit-Hamtramck Assembly plant opened in 1985 and spans two cities - Detroit and Hamtramck. It is the home of GM electric vehicles, including the Chevrolet Volt and Cadillac ELR, and is the company’s most complex plant in North America building five models on one production line. GM has spent more than US$1bn on the plant over the last five years.