There's some confusion as to whether the new Mercedes-Benz AMG SLS GT (to give it its full title) is a replacement or an addition to the SLS stable. The official line is that it is a faster and more focused additional model but it seems likely that the standard SLS will quietly disappear. It make less and less sense in the face of the monstrous SL 63 and 65s now available. The SLS GT, however, makes perfect sense - it fixes the niggle that every single reviewer has complained about since day one. Gearbox, gearbox, gearbox.