DETROIT -- The Cadillac Elmiraj concept, continuing a global tour that began in California last summer, made an appearance in metro Detroit late Friday, drawing admirers and sparking yet another round of speculation about whether General Motors will build the big coupe.

The coupe concept made an unannounced stop at Vinsetta Garage, a former repair shop turned restaurant, along Woodward Avenue in Royal Oak, Mich. Woodward Avenue is the host strip of the annual Dream Cruise in August.

Many onlookers used "spectacular" to describe the car.

Since the Elmiraj debuted in August at the Pebble Beach Concours d'Elegance, General Motors has been gauging reaction from consumers around the world.

And so far, so good. The car attracted another crowd in Detroit.

"It has been so well received wherever it has been shown," Ed Welburn, GM vice president of global design, said in May at the WardsAuto Interiors Conference in Detroit.

Welburn declined to say if GM has decided to build a production version, but said the warm reception for the Elmiraj "is a good sign" and good for Cadillac.

The Elmiraj, powered by a twin turbocharged V-8, would give Cadillac a high-priced flagship against entries from Mercedes-Benz, Bentley and Rolls-Royce.

Talk of Cadillac launching a large, flagship sedan to rival the likes of the BMW 7-Series and Mercedes-Benz S-Class dates back several years, but prototypes for just such a car have been spotted and now we know roughly when we’ll see the covers come off.

A high-level insider at Cadillac has revealed to Autoblog that the brand’s new flagship sedan, expected to be called the LTS, will make its world debut at the 2015 New York Auto Show next April. This suggests that sales will commence in the fall of next year, making the LTS a 2016 model.

The insider said the styling of the car has been inspired by the lines of 2013’s Elmiraj concept car, but unlike the concept, which was a coupe, the new LTS will come with four doors only. Our own spy shots of prototypes reveal a fairly conventional three-box sedan shape, with a long hood and short overhangs.

Underpinning the car is likely to be General Motors Company’s [NYSE:GM] new Omega platform. Designed for large cars, this platform is thought to share much in common with the smaller Alpha design, including a rear-wheel-drive layout with optional all-wheel drive. Engines, meanwhile, should include V-6 and V-8 units, and we could see a hybrid option considering most rivals already offer one.

Expect to hear a great deal more about the new Cadillac flagship before its unveiling next year.