Modern day autos use helical gears and synchromesh equipment in the gearboxes, that synchronize the rotation of gears which are going to mesh. This removes clashing on the gears and will make equipment shifting easier. Many early versions of these transmissions had been semi-automated in operation, for example Autostick, https://gearbox07529.madmouseblog.com/14279616/the-basic-principles-of-gearbox