So, remember that failed electric sports car that Mercedes tried to make happen back in 2013? You know; the one that started out as the SLS AMG E-Cell in 2011 and became a “production” model with the name SLS AMG Electric Drive. Well, I wouldn’t be surprised if you didn’t know what it was, considering not even 100 examples were sold when it went on sale. That was back just a few years ago when the four-motor car was good for all of about 160 miles on a full charge – not even enough to have a full day at the track or a nice Sunday drive. So why was Mercedes just caught testing one on public roads again? It was even caked with all kinds of testing equipment. Clearly, Mercedes has something new in the works. The question is: What?