Our eager spy photographers caught a glimpse of a camouflaged Cadillac ELR undergoing hot-weather testing. The ELR test car was accompanied by a Chevrolet Volt -- no surprise, given that the two-door Cadillac will use the same plug-in hybrid powertrain as the Volt. Last summer, Cadillac confirmed that it would build a range-extended electric car named the ELR. The stylish two-door design had previously been shown in 2009 as the Cadillac Converj concept. Although the company hasn't revealed any more information about the ELR since last August, we believe the electric car is one of ten new models that Cadillac will introduce over the next three years. Expect it to debut next year as a 2014 model. Despite the engineers' best efforts at applying camouflage tape, the front end of this car clearly displays the three-bar grille and corporate crest that are visible on all Cadillacs. The two-door ELR's roof slopes down aft of the B-pillar into a large rear windshield. Overall, the car's proportions, curved front end, and stubby tail are very similar to those of the Chevrolet Volt -- and for good reason, as the two cars share a platform. The swirling, turbine-style alloy wheels from the Converj concept appear to have made it to production, too. Cadillac said in August 2011 that the ELR would have a "T-shaped lithium ion battery", along with a four-cylinder gasoline engine that could allow "driving for hundreds of additional miles" once the battery was depleted. It's quite likely the ELR's drivetrain will be identical to that of the Chevrolet Volt, which uses a T-shaped 16-kWh battery pack and a 1.4-liter inline-four gasoline engine. However, a recent report suggests the 2014 Chevrolet Volt could switch to a 2.0-liter turbo-four range extender engine. That could potentially improve efficiency, and provide extra acceleration for a more luxurious Cadillac electric car. Expect Cadillac to reveal the production ELR next year.