This week, Jeremy Clarkson drives the most important new car to be launched this autumn, the Vauxhall Vectra. It replaces Britain's favourite fleet car, the Cavalier, but how good is it? Meanwhile, Tiff Needell tries the new Saab with electronic kit that enables the driver to change gear without the tedium of using a clutch pedal. Plus, Michele Newman finds out what it takes to enter a motor race when you're a complete novice.