The winding backstreets of London, Paris and Rome are a large part of their charm. But they are also a problem for electric carmakers. For a long time, squeezing big batteries into smaller, cheaper cars to fit European streets was too much of a problem, so manufacturers focused on bloated SUVs instead.But that is finally changing. Battery technology has improved and Europe’s carmakers havecut manufacturing costs enough that they can now sell cars that might have a chance of fitting down a medieval lane or two.The new Renault Twingo E-Tech is a case in point. Driving the city car through...