The Cadillac Converj Concept made its debut at the 2009 Detroit Auto Show and caused quite a stir. Its sleek lines and innovative electric powetrain helped steal the show. But plans to build the car have been on hold, until now. This week, Cadillac confirmed that the Converj Concept will become a reality in the guise of the upcoming ELR. Using technology from the Chevrolet Volt, the angular ELR coupe will be a performance-tuned extended-range electric coupe that may give Teslas a run for their money. “The concept generated instant enthusiasm,” said Don Butler, vice president-Cadillac Marketing….