Been lying awake at night wondering how plug-in cars are doing in Europe? Me, neither, but, having now evaluated a few - Vauxhall Ampera [aka Chevy Volt], Toyota Prius, Volvo V60 with the Mitsubishi Outlander and BMW i3 REX to come - I figured it was time to take a look. Cue the expert number crunchers at UK-based JATO Dynamics.