Cadillac still doesn't have a proper footprint in the world of electric powertrains. We can at last say when it will, however: the automaker has confirmed that it's unveiling the production, 2014 model year ELR coupe on January 15th at the Detroit Auto Show. Few details have surfaced in the teaser image and release, but a mention of "extended-range electric vehicle technology" supports beliefs that the ELR is still using a variant of the Chevy Volt's powerplant, not unlike the Converj concept from 2009. Clues to the bodywork (and recent spy photos) also suggest it won't be much different on the outside. No matter how much has changed, we'll have a better sense of how green GM's luxury marque can be when we're on the show floor in a month's time.