Mercedes-Benz has already committed to bringing the SLS AMG E-Cell gullwing to dealers in 2013, but we'd advise holding back on taking out a second mortgage to pay for it until you're done reading. The Netherlands' De Telegraaf hears from an unnamed spokesperson that there's enough interest to make a roadster version of the EV supercar. What action the automaker takes depends on sales of the hardtop: if it's clear more people want an
