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 open-air experience, that's what will happen. The electric motor layout is easily transferred to a roadster, the representative says. If that E-Cell variant becomes a reality, Audi might want to hurry up and build a production-grade e-tron Spyder before Mercedes claims all of the (very niche) German electric roadster market for itself.