For years, spy photographers made a living shooting camouflaged test cars for eager fans.

Now the auto companies are doing it themselves.

GM today released a photo of the 2014 Cadillac ELR on the road in Southern California, covered in camo, as its second teaser shot for the electric luxury coupe it will unveil next Tuesday at the Detroit Auto Show.

In mid-December, GM had released a first teaser image of the Cadillac ELR, a shadowy side-profile shot that confirmed its essential shape without adding many details.

The range-extended Cadillac will ride on the same underpinnings as the Chevrolet Volt, with an updated version of its Voltec powertrain under the hood.

Some sources suggest the ELR will use an updated version of the Volt's 16-kilowatt-hour lithium-ion battery pack, perhaps even a more powerful 2.0-liter range-extending engine.

Based on the well-received Cadillac Converj concept car that was first unveiled in January 2009, the ELR was green-lighted for production in August 2011.

This site was the first to report that approval, before GM confirmed the news the following week.

GM executives had sought ways to boost plug-in car production at the Detroit-Hamtramck plant where the Chevrolet Volt is built. One method: additional Voltec models.

The Cadillac ELR will likely carry a price north of $40,000 and the usual Cadillac luxury features, presumably including the CUE touchscreen control system that's received mixed reviews.

"Cadillac customers are going to enjoy the unique features ELR will bring to the market," said the ELR's chief engineer, Chris Thomason. "We’re going to change the way people think about luxury and electrification."

Green Car Reports will bring you the news from the Detroit Auto Show as it happens; follow our show news page for all the latest.

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